diff --git a/gfx/layers/Compositor.h b/gfx/layers/Compositor.h
index d3901b9c068b..c9b0aa6ffbe9 100644
--- a/gfx/layers/Compositor.h
+++ b/gfx/layers/Compositor.h
@@ -197,7 +197,7 @@ protected:
 public:
   NS_INLINE_DECL_REFCOUNTING(Compositor)
 
-  Compositor(PCompositorParent* aParent = nullptr)
+  explicit Compositor(PCompositorParent* aParent = nullptr)
     : mCompositorID(0)
     , mDiagnosticTypes(DiagnosticTypes::NO_DIAGNOSTIC)
     , mParent(aParent)
diff --git a/gfx/layers/Effects.h b/gfx/layers/Effects.h
index e52ecdc41f1b..24272b18be74 100644
--- a/gfx/layers/Effects.h
+++ b/gfx/layers/Effects.h
@@ -42,7 +42,7 @@ struct Effect
 {
   NS_INLINE_DECL_REFCOUNTING(Effect)
 
-  Effect(EffectTypes aType) : mType(aType) {}
+  explicit Effect(EffectTypes aType) : mType(aType) {}
 
   EffectTypes mType;
 
@@ -98,7 +98,7 @@ struct EffectMask : public Effect
 
 struct EffectBlendMode : public Effect
 {
-  EffectBlendMode(gfx::CompositionOp aBlendMode)
+  explicit EffectBlendMode(gfx::CompositionOp aBlendMode)
     : Effect(EffectTypes::BLEND_MODE)
     , mBlendMode(aBlendMode)
   { }
@@ -112,7 +112,7 @@ struct EffectBlendMode : public Effect
 // Render to a render target rather than the screen.
 struct EffectRenderTarget : public TexturedEffect
 {
-  EffectRenderTarget(CompositingRenderTarget *aRenderTarget)
+  explicit EffectRenderTarget(CompositingRenderTarget *aRenderTarget)
     : TexturedEffect(EffectTypes::RENDER_TARGET, aRenderTarget, true, gfx::Filter::LINEAR)
     , mRenderTarget(aRenderTarget)
   {}
@@ -183,7 +183,7 @@ struct EffectComponentAlpha : public TexturedEffect
 
 struct EffectSolidColor : public Effect
 {
-  EffectSolidColor(const gfx::Color &aColor)
+  explicit EffectSolidColor(const gfx::Color &aColor)
     : Effect(EffectTypes::SOLID_COLOR)
     , mColor(aColor)
   {}
diff --git a/gfx/layers/ImageContainer.h b/gfx/layers/ImageContainer.h
index 0be6b5b0c2f5..53f97c8ebd95 100644
--- a/gfx/layers/ImageContainer.h
+++ b/gfx/layers/ImageContainer.h
@@ -57,7 +57,7 @@ public:
    */
   class SurfaceReleaser : public nsRunnable {
   public:
-    SurfaceReleaser(RawRef aRef) : mRef(aRef) {}
+    explicit SurfaceReleaser(RawRef aRef) : mRef(aRef) {}
     NS_IMETHOD Run() {
       mRef->Release();
       return NS_OK;
@@ -350,7 +350,7 @@ public:
 
   enum { DISABLE_ASYNC = 0x0, ENABLE_ASYNC = 0x01 };
 
-  ImageContainer(int flag = 0);
+  explicit ImageContainer(int flag = 0);
 
   /**
    * Create an Image in one of the given formats.
@@ -666,7 +666,7 @@ private:
 class AutoLockImage
 {
 public:
-  AutoLockImage(ImageContainer *aContainer) : mContainer(aContainer) { mImage = mContainer->LockCurrentImage(); }
+  explicit AutoLockImage(ImageContainer *aContainer) : mContainer(aContainer) { mImage = mContainer->LockCurrentImage(); }
   AutoLockImage(ImageContainer *aContainer, RefPtr<gfx::SourceSurface> *aSurface) : mContainer(aContainer) {
     *aSurface = mContainer->LockCurrentAsSourceSurface(&mSize, getter_AddRefs(mImage));
   }
@@ -821,7 +821,7 @@ public:
 
   virtual gfx::IntSize GetSize() { return mSize; }
 
-  PlanarYCbCrImage(BufferRecycleBin *aRecycleBin);
+  explicit PlanarYCbCrImage(BufferRecycleBin *aRecycleBin);
 
   virtual SharedPlanarYCbCrImage *AsSharedPlanarYCbCrImage() { return nullptr; }
 
diff --git a/gfx/layers/LayerScope.cpp b/gfx/layers/LayerScope.cpp
index 461188e6930d..649dbbdf702e 100644
--- a/gfx/layers/LayerScope.cpp
+++ b/gfx/layers/LayerScope.cpp
@@ -366,7 +366,7 @@ StaticAutoPtr<LayerScopeWebSocketManager> WebSocketHelper::sWebSocketManager;
  */
 class DebugGLData: public LinkedListElement<DebugGLData> {
 public:
-    DebugGLData(Packet::DataType aDataType)
+    explicit DebugGLData(Packet::DataType aDataType)
         : mDataType(aDataType)
     { }
 
@@ -399,7 +399,7 @@ public:
           mFrameStamp(aValue)
     { }
 
-    DebugGLFrameStatusData(Packet::DataType aDataType)
+    explicit DebugGLFrameStatusData(Packet::DataType aDataType)
         : DebugGLData(aDataType),
           mFrameStamp(0)
     { }
@@ -547,7 +547,7 @@ protected:
 
 class DebugGLLayersData : public DebugGLData {
 public:
-    DebugGLLayersData(UniquePtr<Packet> aPacket)
+    explicit DebugGLLayersData(UniquePtr<Packet> aPacket)
         : DebugGLData(Packet::LAYERS),
           mPacket(Move(aPacket))
     { }
diff --git a/gfx/layers/LayerScope.h b/gfx/layers/LayerScope.h
index 75af91851525..420370ab714c 100644
--- a/gfx/layers/LayerScope.h
+++ b/gfx/layers/LayerScope.h
@@ -41,7 +41,7 @@ public:
 // Perform BeginFrame and EndFrame automatically
 class LayerScopeAutoFrame {
 public:
-    LayerScopeAutoFrame(int64_t aFrameStamp);
+    explicit LayerScopeAutoFrame(int64_t aFrameStamp);
     ~LayerScopeAutoFrame();
 
 private:
diff --git a/gfx/layers/LayerTreeInvalidation.cpp b/gfx/layers/LayerTreeInvalidation.cpp
index d2bba6b3db30..f5b676a1745f 100644
--- a/gfx/layers/LayerTreeInvalidation.cpp
+++ b/gfx/layers/LayerTreeInvalidation.cpp
@@ -98,7 +98,7 @@ NotifySubdocumentInvalidationRecursive(Layer* aLayer, NotifySubDocInvalidationFu
 
 struct LayerPropertiesBase : public LayerProperties
 {
-  LayerPropertiesBase(Layer* aLayer)
+  explicit LayerPropertiesBase(Layer* aLayer)
     : mLayer(aLayer)
     , mMaskLayer(nullptr)
     , mVisibleRegion(aLayer->GetVisibleRegion())
@@ -212,7 +212,7 @@ struct LayerPropertiesBase : public LayerProperties
 
 struct ContainerLayerProperties : public LayerPropertiesBase
 {
-  ContainerLayerProperties(ContainerLayer* aLayer)
+  explicit ContainerLayerProperties(ContainerLayer* aLayer)
     : LayerPropertiesBase(aLayer)
     , mPreXScale(aLayer->GetPreXScale())
     , mPreYScale(aLayer->GetPreYScale())
@@ -322,7 +322,7 @@ struct ContainerLayerProperties : public LayerPropertiesBase
 
 struct ColorLayerProperties : public LayerPropertiesBase
 {
-  ColorLayerProperties(ColorLayer *aLayer)
+  explicit ColorLayerProperties(ColorLayer *aLayer)
     : LayerPropertiesBase(aLayer)
     , mColor(aLayer->GetColor())
   { }
@@ -345,7 +345,7 @@ struct ColorLayerProperties : public LayerPropertiesBase
 
 struct ImageLayerProperties : public LayerPropertiesBase
 {
-  ImageLayerProperties(ImageLayer* aImage)
+  explicit ImageLayerProperties(ImageLayer* aImage)
     : LayerPropertiesBase(aImage)
     , mContainer(aImage->GetContainer())
     , mFilter(aImage->GetFilter())
diff --git a/gfx/layers/RotatedBuffer.h b/gfx/layers/RotatedBuffer.h
index 0c7c4ba9ade2..c2e098ee6bd2 100644
--- a/gfx/layers/RotatedBuffer.h
+++ b/gfx/layers/RotatedBuffer.h
@@ -190,7 +190,7 @@ public:
     ContainsVisibleBounds
   };
 
-  RotatedContentBuffer(BufferSizePolicy aBufferSizePolicy)
+  explicit RotatedContentBuffer(BufferSizePolicy aBufferSizePolicy)
     : mBufferProvider(nullptr)
     , mBufferProviderOnWhite(nullptr)
     , mBufferSizePolicy(aBufferSizePolicy)
diff --git a/gfx/layers/apz/src/AsyncPanZoomController.cpp b/gfx/layers/apz/src/AsyncPanZoomController.cpp
index 38011932c949..1af97417d311 100644
--- a/gfx/layers/apz/src/AsyncPanZoomController.cpp
+++ b/gfx/layers/apz/src/AsyncPanZoomController.cpp
@@ -646,7 +646,7 @@ private:
 
 class OverscrollSnapBackAnimation: public AsyncPanZoomAnimation {
 public:
-  OverscrollSnapBackAnimation(AsyncPanZoomController& aApzc)
+  explicit OverscrollSnapBackAnimation(AsyncPanZoomController& aApzc)
     : mApzc(aApzc)
   {
     // Make sure the initial velocity is zero. This is normally the case
diff --git a/gfx/layers/apz/src/AsyncPanZoomController.h b/gfx/layers/apz/src/AsyncPanZoomController.h
index a8d578a14ebf..3bc6eb857482 100644
--- a/gfx/layers/apz/src/AsyncPanZoomController.h
+++ b/gfx/layers/apz/src/AsyncPanZoomController.h
@@ -1074,8 +1074,8 @@ class AsyncPanZoomAnimation {
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(AsyncPanZoomAnimation)
 
 public:
-  AsyncPanZoomAnimation(const TimeDuration& aRepaintInterval =
-                        TimeDuration::Forever())
+  explicit AsyncPanZoomAnimation(const TimeDuration& aRepaintInterval =
+                                 TimeDuration::Forever())
     : mRepaintInterval(aRepaintInterval)
   { }
 
diff --git a/gfx/layers/apz/src/Axis.h b/gfx/layers/apz/src/Axis.h
index 1aa37e0410c9..d365f754b3a2 100644
--- a/gfx/layers/apz/src/Axis.h
+++ b/gfx/layers/apz/src/Axis.h
@@ -35,7 +35,7 @@ class AsyncPanZoomController;
  */
 class Axis {
 public:
-  Axis(AsyncPanZoomController* aAsyncPanZoomController);
+  explicit Axis(AsyncPanZoomController* aAsyncPanZoomController);
 
   enum Overscroll {
     // Overscroll is not happening at all.
@@ -246,7 +246,7 @@ protected:
 
 class AxisX : public Axis {
 public:
-  AxisX(AsyncPanZoomController* mAsyncPanZoomController);
+  explicit AxisX(AsyncPanZoomController* mAsyncPanZoomController);
   virtual CSSCoord GetPointOffset(const CSSPoint& aPoint) const;
   virtual CSSCoord GetRectLength(const CSSRect& aRect) const;
   virtual CSSCoord GetRectOffset(const CSSRect& aRect) const;
@@ -254,7 +254,7 @@ public:
 
 class AxisY : public Axis {
 public:
-  AxisY(AsyncPanZoomController* mAsyncPanZoomController);
+  explicit AxisY(AsyncPanZoomController* mAsyncPanZoomController);
   virtual CSSCoord GetPointOffset(const CSSPoint& aPoint) const;
   virtual CSSCoord GetRectLength(const CSSRect& aRect) const;
   virtual CSSCoord GetRectOffset(const CSSRect& aRect) const;
diff --git a/gfx/layers/apz/src/GestureEventListener.h b/gfx/layers/apz/src/GestureEventListener.h
index 5a12417eca67..fc5e31049994 100644
--- a/gfx/layers/apz/src/GestureEventListener.h
+++ b/gfx/layers/apz/src/GestureEventListener.h
@@ -40,7 +40,7 @@ class GestureEventListener MOZ_FINAL {
 public:
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(GestureEventListener)
 
-  GestureEventListener(AsyncPanZoomController* aAsyncPanZoomController);
+  explicit GestureEventListener(AsyncPanZoomController* aAsyncPanZoomController);
 
   // --------------------------------------------------------------------------
   // These methods must only be called on the controller/UI thread.
diff --git a/gfx/layers/basic/BasicCanvasLayer.h b/gfx/layers/basic/BasicCanvasLayer.h
index d3fb3a7ce187..f76e593912bf 100644
--- a/gfx/layers/basic/BasicCanvasLayer.h
+++ b/gfx/layers/basic/BasicCanvasLayer.h
@@ -22,7 +22,7 @@ class BasicCanvasLayer : public CopyableCanvasLayer,
                          public BasicImplData
 {
 public:
-  BasicCanvasLayer(BasicLayerManager* aLayerManager) :
+  explicit BasicCanvasLayer(BasicLayerManager* aLayerManager) :
     CopyableCanvasLayer(aLayerManager,
                         static_cast<BasicImplData*>(MOZ_THIS_IN_INITIALIZER_LIST()))
   { }
diff --git a/gfx/layers/basic/BasicColorLayer.cpp b/gfx/layers/basic/BasicColorLayer.cpp
index d5633efd717d..bcca4656a712 100644
--- a/gfx/layers/basic/BasicColorLayer.cpp
+++ b/gfx/layers/basic/BasicColorLayer.cpp
@@ -26,7 +26,7 @@ namespace layers {
 
 class BasicColorLayer : public ColorLayer, public BasicImplData {
 public:
-  BasicColorLayer(BasicLayerManager* aLayerManager) :
+  explicit BasicColorLayer(BasicLayerManager* aLayerManager) :
     ColorLayer(aLayerManager,
                static_cast<BasicImplData*>(MOZ_THIS_IN_INITIALIZER_LIST()))
   {
diff --git a/gfx/layers/basic/BasicCompositor.h b/gfx/layers/basic/BasicCompositor.h
index 0c0c5ef25342..f09192ee0294 100644
--- a/gfx/layers/basic/BasicCompositor.h
+++ b/gfx/layers/basic/BasicCompositor.h
@@ -40,7 +40,7 @@ public:
 class BasicCompositor : public Compositor
 {
 public:
-  BasicCompositor(nsIWidget *aWidget);
+  explicit BasicCompositor(nsIWidget *aWidget);
 
 protected:
   virtual ~BasicCompositor();
diff --git a/gfx/layers/basic/BasicContainerLayer.h b/gfx/layers/basic/BasicContainerLayer.h
index f18d635dc363..7cc2f6dbcab8 100644
--- a/gfx/layers/basic/BasicContainerLayer.h
+++ b/gfx/layers/basic/BasicContainerLayer.h
@@ -19,7 +19,7 @@ namespace layers {
 
 class BasicContainerLayer : public ContainerLayer, public BasicImplData {
 public:
-  BasicContainerLayer(BasicLayerManager* aManager) :
+  explicit BasicContainerLayer(BasicLayerManager* aManager) :
     ContainerLayer(aManager,
                    static_cast<BasicImplData*>(MOZ_THIS_IN_INITIALIZER_LIST()))
   {
diff --git a/gfx/layers/basic/BasicImageLayer.cpp b/gfx/layers/basic/BasicImageLayer.cpp
index 32220b35a105..8f027f88fb8f 100644
--- a/gfx/layers/basic/BasicImageLayer.cpp
+++ b/gfx/layers/basic/BasicImageLayer.cpp
@@ -25,7 +25,7 @@ namespace layers {
 
 class BasicImageLayer : public ImageLayer, public BasicImplData {
 public:
-  BasicImageLayer(BasicLayerManager* aLayerManager) :
+  explicit BasicImageLayer(BasicLayerManager* aLayerManager) :
     ImageLayer(aLayerManager,
                static_cast<BasicImplData*>(MOZ_THIS_IN_INITIALIZER_LIST())),
     mSize(-1, -1)
diff --git a/gfx/layers/basic/BasicLayers.h b/gfx/layers/basic/BasicLayers.h
index d95f93fb6fd0..215c8279580d 100644
--- a/gfx/layers/basic/BasicLayers.h
+++ b/gfx/layers/basic/BasicLayers.h
@@ -56,7 +56,7 @@ public:
    * must be called for any rendering to happen. ThebesLayers will not
    * be retained.
    */
-  BasicLayerManager(BasicLayerManagerType aType);
+  explicit BasicLayerManager(BasicLayerManagerType aType);
   /**
    * Construct a BasicLayerManager which will have no default
    * target context. SetDefaultTarget or BeginTransactionWithTarget
@@ -72,7 +72,7 @@ public:
    * must ensure that the widget outlives the layer manager or call
    * ClearWidget before the widget dies.
    */
-  BasicLayerManager(nsIWidget* aWidget);
+  explicit BasicLayerManager(nsIWidget* aWidget);
 
 protected:
   virtual ~BasicLayerManager();
diff --git a/gfx/layers/basic/BasicLayersImpl.h b/gfx/layers/basic/BasicLayersImpl.h
index 2fba7224f738..7a5926b4475e 100644
--- a/gfx/layers/basic/BasicLayersImpl.h
+++ b/gfx/layers/basic/BasicLayersImpl.h
@@ -49,7 +49,7 @@ class BasicReadbackLayer : public ReadbackLayer,
                            public BasicImplData
 {
 public:
-  BasicReadbackLayer(BasicLayerManager* aLayerManager) :
+  explicit BasicReadbackLayer(BasicLayerManager* aLayerManager) :
     ReadbackLayer(aLayerManager,
                   static_cast<BasicImplData*>(MOZ_THIS_IN_INITIALIZER_LIST()))
   {
diff --git a/gfx/layers/basic/BasicThebesLayer.h b/gfx/layers/basic/BasicThebesLayer.h
index 0a2b0a0b85ec..ffbbe8259b27 100644
--- a/gfx/layers/basic/BasicThebesLayer.h
+++ b/gfx/layers/basic/BasicThebesLayer.h
@@ -30,7 +30,7 @@ public:
   typedef RotatedContentBuffer::PaintState PaintState;
   typedef RotatedContentBuffer::ContentType ContentType;
 
-  BasicThebesLayer(BasicLayerManager* aLayerManager) :
+  explicit BasicThebesLayer(BasicLayerManager* aLayerManager) :
     ThebesLayer(aLayerManager,
                 static_cast<BasicImplData*>(MOZ_THIS_IN_INITIALIZER_LIST())),
     mContentClient(nullptr)
diff --git a/gfx/layers/client/ClientCanvasLayer.h b/gfx/layers/client/ClientCanvasLayer.h
index 591319f4bce0..b9de0fce0da7 100644
--- a/gfx/layers/client/ClientCanvasLayer.h
+++ b/gfx/layers/client/ClientCanvasLayer.h
@@ -36,7 +36,7 @@ class ClientCanvasLayer : public CopyableCanvasLayer,
 {
   typedef CanvasClient::CanvasClientType CanvasClientType;
 public:
-  ClientCanvasLayer(ClientLayerManager* aLayerManager) :
+  explicit ClientCanvasLayer(ClientLayerManager* aLayerManager) :
     CopyableCanvasLayer(aLayerManager,
                         static_cast<ClientLayer*>(MOZ_THIS_IN_INITIALIZER_LIST()))
     , mTextureSurface(nullptr)
diff --git a/gfx/layers/client/ClientColorLayer.cpp b/gfx/layers/client/ClientColorLayer.cpp
index 1b49c07f2129..29038de37e7f 100644
--- a/gfx/layers/client/ClientColorLayer.cpp
+++ b/gfx/layers/client/ClientColorLayer.cpp
@@ -21,7 +21,7 @@ using namespace mozilla::gfx;
 class ClientColorLayer : public ColorLayer, 
                          public ClientLayer {
 public:
-  ClientColorLayer(ClientLayerManager* aLayerManager) :
+  explicit ClientColorLayer(ClientLayerManager* aLayerManager) :
     ColorLayer(aLayerManager,
                static_cast<ClientLayer*>(MOZ_THIS_IN_INITIALIZER_LIST()))
   {
diff --git a/gfx/layers/client/ClientContainerLayer.h b/gfx/layers/client/ClientContainerLayer.h
index 23329689c0a2..f82e65f166b6 100644
--- a/gfx/layers/client/ClientContainerLayer.h
+++ b/gfx/layers/client/ClientContainerLayer.h
@@ -27,7 +27,7 @@ class ClientContainerLayer : public ContainerLayer,
                              public ClientLayer
 {
 public:
-  ClientContainerLayer(ClientLayerManager* aManager) :
+  explicit ClientContainerLayer(ClientLayerManager* aManager) :
     ContainerLayer(aManager,
                    static_cast<ClientLayer*>(MOZ_THIS_IN_INITIALIZER_LIST()))
   {
@@ -150,7 +150,7 @@ protected:
 class ClientRefLayer : public RefLayer,
                        public ClientLayer {
 public:
-  ClientRefLayer(ClientLayerManager* aManager) :
+  explicit ClientRefLayer(ClientLayerManager* aManager) :
     RefLayer(aManager,
              static_cast<ClientLayer*>(MOZ_THIS_IN_INITIALIZER_LIST()))
   {
diff --git a/gfx/layers/client/ClientImageLayer.cpp b/gfx/layers/client/ClientImageLayer.cpp
index e016ba521134..2d348d7d3691 100644
--- a/gfx/layers/client/ClientImageLayer.cpp
+++ b/gfx/layers/client/ClientImageLayer.cpp
@@ -26,7 +26,7 @@ using namespace mozilla::gfx;
 class ClientImageLayer : public ImageLayer, 
                          public ClientLayer {
 public:
-  ClientImageLayer(ClientLayerManager* aLayerManager)
+  explicit ClientImageLayer(ClientLayerManager* aLayerManager)
     : ImageLayer(aLayerManager,
                  static_cast<ClientLayer*>(MOZ_THIS_IN_INITIALIZER_LIST()))
     , mImageClientTypeContainer(CompositableType::BUFFER_UNKNOWN)
diff --git a/gfx/layers/client/ClientLayerManager.h b/gfx/layers/client/ClientLayerManager.h
index f5dd326738ae..dfdfa39724f9 100644
--- a/gfx/layers/client/ClientLayerManager.h
+++ b/gfx/layers/client/ClientLayerManager.h
@@ -43,7 +43,7 @@ class ClientLayerManager : public LayerManager
   typedef nsTArray<nsRefPtr<Layer> > LayerRefArray;
 
 public:
-  ClientLayerManager(nsIWidget* aWidget);
+  explicit ClientLayerManager(nsIWidget* aWidget);
 
 protected:
   virtual ~ClientLayerManager();
diff --git a/gfx/layers/client/ClientReadbackLayer.h b/gfx/layers/client/ClientReadbackLayer.h
index f3046fea8115..89e673306088 100644
--- a/gfx/layers/client/ClientReadbackLayer.h
+++ b/gfx/layers/client/ClientReadbackLayer.h
@@ -17,7 +17,7 @@ class ClientReadbackLayer :
   public ClientLayer
 {
 public:
-    ClientReadbackLayer(ClientLayerManager *aManager)
+  explicit ClientReadbackLayer(ClientLayerManager *aManager)
     : ReadbackLayer(aManager, nullptr)
   {
       mImplData = static_cast<ClientLayer*>(this);
diff --git a/gfx/layers/client/ClientThebesLayer.h b/gfx/layers/client/ClientThebesLayer.h
index b5864ef448f4..01b7513973d7 100644
--- a/gfx/layers/client/ClientThebesLayer.h
+++ b/gfx/layers/client/ClientThebesLayer.h
@@ -33,8 +33,8 @@ public:
   typedef RotatedContentBuffer::PaintState PaintState;
   typedef RotatedContentBuffer::ContentType ContentType;
 
-  ClientThebesLayer(ClientLayerManager* aLayerManager,
-                    LayerManager::ThebesLayerCreationHint aCreationHint = LayerManager::NONE) :
+  explicit ClientThebesLayer(ClientLayerManager* aLayerManager,
+                             LayerManager::ThebesLayerCreationHint aCreationHint = LayerManager::NONE) :
     ThebesLayer(aLayerManager,
                 static_cast<ClientLayer*>(MOZ_THIS_IN_INITIALIZER_LIST()),
                 aCreationHint),
diff --git a/gfx/layers/client/ClientTiledThebesLayer.h b/gfx/layers/client/ClientTiledThebesLayer.h
index da3fe6a75913..f4539ee3fc49 100644
--- a/gfx/layers/client/ClientTiledThebesLayer.h
+++ b/gfx/layers/client/ClientTiledThebesLayer.h
@@ -41,8 +41,8 @@ class ClientTiledThebesLayer : public ThebesLayer,
   typedef ThebesLayer Base;
 
 public:
-  ClientTiledThebesLayer(ClientLayerManager* const aManager,
-                         ClientLayerManager::ThebesLayerCreationHint aCreationHint = LayerManager::NONE);
+  explicit ClientTiledThebesLayer(ClientLayerManager* const aManager,
+                                  ClientLayerManager::ThebesLayerCreationHint aCreationHint = LayerManager::NONE);
 
 protected:
   ~ClientTiledThebesLayer();
diff --git a/gfx/layers/client/CompositableClient.h b/gfx/layers/client/CompositableClient.h
index 63293c88f66e..9efa601865ef 100644
--- a/gfx/layers/client/CompositableClient.h
+++ b/gfx/layers/client/CompositableClient.h
@@ -123,7 +123,7 @@ protected:
 public:
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(CompositableClient)
 
-  CompositableClient(CompositableForwarder* aForwarder, TextureFlags aFlags = TextureFlags::NO_FLAGS);
+  explicit CompositableClient(CompositableForwarder* aForwarder, TextureFlags aFlags = TextureFlags::NO_FLAGS);
 
   virtual TextureInfo GetTextureInfo() const = 0;
 
@@ -246,8 +246,8 @@ protected:
  */
 struct AutoRemoveTexture
 {
-  AutoRemoveTexture(CompositableClient* aCompositable,
-                    TextureClient* aTexture = nullptr)
+  explicit AutoRemoveTexture(CompositableClient* aCompositable,
+                             TextureClient* aTexture = nullptr)
     : mTexture(aTexture)
     , mCompositable(aCompositable)
   {}
diff --git a/gfx/layers/client/ContentClient.h b/gfx/layers/client/ContentClient.h
index a31a3eaea474..0fd083c15190 100644
--- a/gfx/layers/client/ContentClient.h
+++ b/gfx/layers/client/ContentClient.h
@@ -83,7 +83,7 @@ public:
    */
   static TemporaryRef<ContentClient> CreateContentClient(CompositableForwarder* aFwd);
 
-  ContentClient(CompositableForwarder* aForwarder)
+  explicit ContentClient(CompositableForwarder* aForwarder)
   : CompositableClient(aForwarder)
   {}
   virtual ~ContentClient()
@@ -113,7 +113,7 @@ public:
 class ContentClientRemote : public ContentClient
 {
 public:
-  ContentClientRemote(CompositableForwarder* aForwarder)
+  explicit ContentClientRemote(CompositableForwarder* aForwarder)
     : ContentClient(aForwarder)
   {}
 
@@ -190,7 +190,7 @@ class ContentClientRemoteBuffer : public ContentClientRemote
   using RotatedContentBuffer::BufferRect;
   using RotatedContentBuffer::BufferRotation;
 public:
-  ContentClientRemoteBuffer(CompositableForwarder* aForwarder)
+  explicit ContentClientRemoteBuffer(CompositableForwarder* aForwarder)
     : ContentClientRemote(aForwarder)
     , RotatedContentBuffer(ContainsVisibleBounds)
     , mIsNewBuffer(false)
@@ -315,7 +315,7 @@ protected:
 class ContentClientDoubleBuffered : public ContentClientRemoteBuffer
 {
 public:
-  ContentClientDoubleBuffered(CompositableForwarder* aFwd)
+  explicit ContentClientDoubleBuffered(CompositableForwarder* aFwd)
     : ContentClientRemoteBuffer(aFwd)
   {
     mTextureInfo.mCompositableType = CompositableType::CONTENT_DOUBLE;
@@ -374,7 +374,7 @@ private:
 class ContentClientSingleBuffered : public ContentClientRemoteBuffer
 {
 public:
-  ContentClientSingleBuffered(CompositableForwarder* aFwd)
+  explicit ContentClientSingleBuffered(CompositableForwarder* aFwd)
     : ContentClientRemoteBuffer(aFwd)
   {
     mTextureInfo.mCompositableType = CompositableType::CONTENT_SINGLE;
@@ -394,7 +394,7 @@ class ContentClientIncremental : public ContentClientRemote
                                , public BorrowDrawTarget
 {
 public:
-  ContentClientIncremental(CompositableForwarder* aFwd)
+  explicit ContentClientIncremental(CompositableForwarder* aFwd)
     : ContentClientRemote(aFwd)
     , mContentType(gfxContentType::COLOR_ALPHA)
     , mHasBuffer(false)
diff --git a/gfx/layers/client/SimpleTiledContentClient.h b/gfx/layers/client/SimpleTiledContentClient.h
index 0eea5458199d..31d43d9f68f9 100644
--- a/gfx/layers/client/SimpleTiledContentClient.h
+++ b/gfx/layers/client/SimpleTiledContentClient.h
@@ -163,8 +163,8 @@ class SimpleClientTiledThebesLayer : public ThebesLayer,
   typedef ThebesLayer Base;
 
 public:
-  SimpleClientTiledThebesLayer(ClientLayerManager* const aManager,
-                               ClientLayerManager::ThebesLayerCreationHint aCreationHint = LayerManager::NONE);
+  explicit SimpleClientTiledThebesLayer(ClientLayerManager* const aManager,
+                                        ClientLayerManager::ThebesLayerCreationHint aCreationHint = LayerManager::NONE);
 protected:
   ~SimpleClientTiledThebesLayer();
 
diff --git a/gfx/layers/client/TextureClient.h b/gfx/layers/client/TextureClient.h
index f87152d57782..5c344caea826 100644
--- a/gfx/layers/client/TextureClient.h
+++ b/gfx/layers/client/TextureClient.h
@@ -137,7 +137,7 @@ class TextureClient
   : public AtomicRefCountedWithFinalize<TextureClient>
 {
 public:
-  TextureClient(TextureFlags aFlags = TextureFlags::DEFAULT);
+  explicit TextureClient(TextureFlags aFlags = TextureFlags::DEFAULT);
   virtual ~TextureClient();
 
   // Creates and allocates a TextureClient usable with Moz2D.
@@ -465,7 +465,7 @@ protected:
 class TextureClientReleaseTask : public Task
 {
 public:
-    TextureClientReleaseTask(TextureClient* aClient)
+    explicit TextureClientReleaseTask(TextureClient* aClient)
         : mTextureClient(aClient) {
     }
 
@@ -620,7 +620,7 @@ protected:
 class StreamTextureClient : public TextureClient
 {
 public:
-  StreamTextureClient(TextureFlags aFlags);
+  explicit StreamTextureClient(TextureFlags aFlags);
 
 protected:
   ~StreamTextureClient();
@@ -669,7 +669,7 @@ struct TextureClientAutoUnlock
 {
   TextureClient* mTexture;
 
-  TextureClientAutoUnlock(TextureClient* aTexture)
+  explicit TextureClientAutoUnlock(TextureClient* aTexture)
   : mTexture(aTexture) {}
 
   ~TextureClientAutoUnlock()
@@ -688,7 +688,7 @@ template<typename T>
 class TKeepAlive : public KeepAlive
 {
 public:
-  TKeepAlive(T* aData) : mData(aData) {}
+  explicit TKeepAlive(T* aData) : mData(aData) {}
 protected:
   RefPtr<T> mData;
 };
diff --git a/gfx/layers/client/TiledContentClient.h b/gfx/layers/client/TiledContentClient.h
index cf62128274a5..dba6a3836ced 100644
--- a/gfx/layers/client/TiledContentClient.h
+++ b/gfx/layers/client/TiledContentClient.h
@@ -97,7 +97,7 @@ private:
   };
 
 public:
-  gfxShmSharedReadLock(ISurfaceAllocator* aAllocator);
+  explicit gfxShmSharedReadLock(ISurfaceAllocator* aAllocator);
 
 protected:
   ~gfxShmSharedReadLock();
diff --git a/gfx/layers/composite/AsyncCompositionManager.h b/gfx/layers/composite/AsyncCompositionManager.h
index 1253badfb8e4..17af6acf27c6 100644
--- a/gfx/layers/composite/AsyncCompositionManager.h
+++ b/gfx/layers/composite/AsyncCompositionManager.h
@@ -28,8 +28,8 @@ class AutoResolveRefLayers;
 
 // Represents (affine) transforms that are calculated from a content view.
 struct ViewTransform {
-  ViewTransform(ParentLayerToScreenScale aScale = ParentLayerToScreenScale(),
-                ScreenPoint aTranslation = ScreenPoint())
+  explicit ViewTransform(ParentLayerToScreenScale aScale = ParentLayerToScreenScale(),
+                         ScreenPoint aTranslation = ScreenPoint())
     : mScale(aScale)
     , mTranslation(aTranslation)
   {}
@@ -76,7 +76,7 @@ class AsyncCompositionManager MOZ_FINAL
 public:
   NS_INLINE_DECL_REFCOUNTING(AsyncCompositionManager)
 
-  AsyncCompositionManager(LayerManagerComposite* aManager)
+  explicit AsyncCompositionManager(LayerManagerComposite* aManager)
     : mLayerManager(aManager)
     , mIsFirstPaint(false)
     , mLayersUpdated(false)
@@ -207,7 +207,7 @@ private:
 
 class MOZ_STACK_CLASS AutoResolveRefLayers {
 public:
-  AutoResolveRefLayers(AsyncCompositionManager* aManager) : mManager(aManager)
+  explicit AutoResolveRefLayers(AsyncCompositionManager* aManager) : mManager(aManager)
   {
     if (mManager) {
       mManager->ResolveRefLayers();
diff --git a/gfx/layers/composite/CanvasLayerComposite.h b/gfx/layers/composite/CanvasLayerComposite.h
index 70f54fa223d4..6051d974ae1f 100644
--- a/gfx/layers/composite/CanvasLayerComposite.h
+++ b/gfx/layers/composite/CanvasLayerComposite.h
@@ -28,7 +28,7 @@ class CanvasLayerComposite : public CanvasLayer,
                              public LayerComposite
 {
 public:
-  CanvasLayerComposite(LayerManagerComposite* aManager);
+  explicit CanvasLayerComposite(LayerManagerComposite* aManager);
 
 protected:
   virtual ~CanvasLayerComposite();
diff --git a/gfx/layers/composite/ColorLayerComposite.h b/gfx/layers/composite/ColorLayerComposite.h
index 31ec0459d709..8414e8a30363 100644
--- a/gfx/layers/composite/ColorLayerComposite.h
+++ b/gfx/layers/composite/ColorLayerComposite.h
@@ -23,7 +23,7 @@ class ColorLayerComposite : public ColorLayer,
                             public LayerComposite
 {
 public:
-  ColorLayerComposite(LayerManagerComposite *aManager)
+  explicit ColorLayerComposite(LayerManagerComposite *aManager)
     : ColorLayer(aManager, nullptr)
     , LayerComposite(aManager)
   {
diff --git a/gfx/layers/composite/CompositableHost.h b/gfx/layers/composite/CompositableHost.h
index 33a2f4b16efe..f4613c3b0c38 100644
--- a/gfx/layers/composite/CompositableHost.h
+++ b/gfx/layers/composite/CompositableHost.h
@@ -88,7 +88,7 @@ protected:
 
 public:
   NS_INLINE_DECL_REFCOUNTING(CompositableHost)
-  CompositableHost(const TextureInfo& aTextureInfo);
+  explicit CompositableHost(const TextureInfo& aTextureInfo);
 
   static TemporaryRef<CompositableHost> Create(const TextureInfo& aTextureInfo);
 
@@ -304,7 +304,7 @@ protected:
 class AutoLockCompositableHost MOZ_FINAL
 {
 public:
-  AutoLockCompositableHost(CompositableHost* aHost)
+  explicit AutoLockCompositableHost(CompositableHost* aHost)
     : mHost(aHost)
   {
     mSucceeded = mHost->Lock();
diff --git a/gfx/layers/composite/ContainerLayerComposite.h b/gfx/layers/composite/ContainerLayerComposite.h
index c3cbc594f301..15518617de35 100644
--- a/gfx/layers/composite/ContainerLayerComposite.h
+++ b/gfx/layers/composite/ContainerLayerComposite.h
@@ -53,7 +53,7 @@ class ContainerLayerComposite : public ContainerLayer,
                         const nsIntRect& aClipRect);
 
 public:
-  ContainerLayerComposite(LayerManagerComposite *aManager);
+  explicit ContainerLayerComposite(LayerManagerComposite *aManager);
 
 protected:
   ~ContainerLayerComposite();
@@ -117,7 +117,7 @@ class RefLayerComposite : public RefLayer,
                         const nsIntRect& aClipRect);
 
 public:
-  RefLayerComposite(LayerManagerComposite *aManager);
+  explicit RefLayerComposite(LayerManagerComposite *aManager);
 
 protected:
   ~RefLayerComposite();
diff --git a/gfx/layers/composite/ContentHost.h b/gfx/layers/composite/ContentHost.h
index e5aa7156aa9d..8270e79d18f1 100644
--- a/gfx/layers/composite/ContentHost.h
+++ b/gfx/layers/composite/ContentHost.h
@@ -68,7 +68,7 @@ public:
   bool PaintWillResample() { return mPaintWillResample; }
 
 protected:
-  ContentHost(const TextureInfo& aTextureInfo)
+  explicit ContentHost(const TextureInfo& aTextureInfo)
     : CompositableHost(aTextureInfo)
     , mPaintWillResample(false)
   {}
@@ -93,7 +93,7 @@ public:
   typedef RotatedContentBuffer::ContentType ContentType;
   typedef RotatedContentBuffer::PaintState PaintState;
 
-  ContentHostBase(const TextureInfo& aTextureInfo);
+  explicit ContentHostBase(const TextureInfo& aTextureInfo);
   virtual ~ContentHostBase();
 
   virtual void Composite(EffectChain& aEffectChain,
@@ -127,7 +127,7 @@ protected:
 class ContentHostTexture : public ContentHostBase
 {
 public:
-  ContentHostTexture(const TextureInfo& aTextureInfo)
+  explicit ContentHostTexture(const TextureInfo& aTextureInfo)
     : ContentHostBase(aTextureInfo)
     , mLocked(false)
   { }
@@ -201,7 +201,7 @@ protected:
 class ContentHostDoubleBuffered : public ContentHostTexture
 {
 public:
-  ContentHostDoubleBuffered(const TextureInfo& aTextureInfo)
+  explicit ContentHostDoubleBuffered(const TextureInfo& aTextureInfo)
     : ContentHostTexture(aTextureInfo)
   {}
 
@@ -225,7 +225,7 @@ protected:
 class ContentHostSingleBuffered : public ContentHostTexture
 {
 public:
-  ContentHostSingleBuffered(const TextureInfo& aTextureInfo)
+  explicit ContentHostSingleBuffered(const TextureInfo& aTextureInfo)
     : ContentHostTexture(aTextureInfo)
   {}
   virtual ~ContentHostSingleBuffered() {}
@@ -251,7 +251,7 @@ public:
 class ContentHostIncremental : public ContentHostBase
 {
 public:
-  ContentHostIncremental(const TextureInfo& aTextureInfo);
+  explicit ContentHostIncremental(const TextureInfo& aTextureInfo);
   ~ContentHostIncremental();
 
   virtual CompositableType GetType() { return CompositableType::BUFFER_CONTENT_INC; }
diff --git a/gfx/layers/composite/FPSCounter.h b/gfx/layers/composite/FPSCounter.h
index e07b9d6df821..2a493d3e4f01 100644
--- a/gfx/layers/composite/FPSCounter.h
+++ b/gfx/layers/composite/FPSCounter.h
@@ -58,7 +58,7 @@ const int kMaxFrames = 2400;
  */
 class FPSCounter {
 public:
-  FPSCounter(const char* aName);
+  explicit FPSCounter(const char* aName);
   ~FPSCounter();
 
   void AddFrame(TimeStamp aTimestamp);
diff --git a/gfx/layers/composite/ImageHost.h b/gfx/layers/composite/ImageHost.h
index bae8ed772072..79f249b7a90f 100644
--- a/gfx/layers/composite/ImageHost.h
+++ b/gfx/layers/composite/ImageHost.h
@@ -40,7 +40,7 @@ struct EffectChain;
 class ImageHost : public CompositableHost
 {
 public:
-  ImageHost(const TextureInfo& aTextureInfo);
+  explicit ImageHost(const TextureInfo& aTextureInfo);
   ~ImageHost();
 
   virtual CompositableType GetType() { return mTextureInfo.mCompositableType; }
diff --git a/gfx/layers/composite/ImageLayerComposite.h b/gfx/layers/composite/ImageLayerComposite.h
index 50dd30a12b31..faded30bbac2 100644
--- a/gfx/layers/composite/ImageLayerComposite.h
+++ b/gfx/layers/composite/ImageLayerComposite.h
@@ -31,7 +31,7 @@ class ImageLayerComposite : public ImageLayer,
   typedef gl::TextureImage TextureImage;
 
 public:
-  ImageLayerComposite(LayerManagerComposite* aManager);
+  explicit ImageLayerComposite(LayerManagerComposite* aManager);
 
 protected:
   virtual ~ImageLayerComposite();
diff --git a/gfx/layers/composite/LayerManagerComposite.h b/gfx/layers/composite/LayerManagerComposite.h
index b7589c635984..901c8bf6fdda 100644
--- a/gfx/layers/composite/LayerManagerComposite.h
+++ b/gfx/layers/composite/LayerManagerComposite.h
@@ -73,7 +73,7 @@ class LayerManagerComposite : public LayerManager
   typedef mozilla::gfx::SurfaceFormat SurfaceFormat;
 
 public:
-  LayerManagerComposite(Compositor* aCompositor);
+  explicit LayerManagerComposite(Compositor* aCompositor);
   ~LayerManagerComposite();
 
   virtual void Destroy() MOZ_OVERRIDE;
@@ -315,7 +315,7 @@ private:
 class LayerComposite
 {
 public:
-  LayerComposite(LayerManagerComposite* aManager);
+  explicit LayerComposite(LayerManagerComposite* aManager);
 
   virtual ~LayerComposite();
 
diff --git a/gfx/layers/composite/TextRenderer.h b/gfx/layers/composite/TextRenderer.h
index 97031c9ecfb1..30cb22cfccfa 100644
--- a/gfx/layers/composite/TextRenderer.h
+++ b/gfx/layers/composite/TextRenderer.h
@@ -22,7 +22,7 @@ class TextRenderer
 public:
   NS_INLINE_DECL_REFCOUNTING(TextRenderer)
 
-  TextRenderer(Compositor *aCompositor)
+  explicit TextRenderer(Compositor *aCompositor)
     : mCompositor(aCompositor)
   {
   }
diff --git a/gfx/layers/composite/TextureHost.cpp b/gfx/layers/composite/TextureHost.cpp
index ed22f1fa7dab..a0b2044f5770 100644
--- a/gfx/layers/composite/TextureHost.cpp
+++ b/gfx/layers/composite/TextureHost.cpp
@@ -71,7 +71,7 @@ namespace layers {
 class TextureParent : public PTextureParent
 {
 public:
-  TextureParent(CompositableParentManager* aManager);
+  explicit TextureParent(CompositableParentManager* aManager);
 
   ~TextureParent();
 
diff --git a/gfx/layers/composite/TextureHost.h b/gfx/layers/composite/TextureHost.h
index e22f0b2963c8..4cb8455fc7b8 100644
--- a/gfx/layers/composite/TextureHost.h
+++ b/gfx/layers/composite/TextureHost.h
@@ -286,7 +286,7 @@ class TextureHost
 
   friend class AtomicRefCountedWithFinalize<TextureHost>;
 public:
-  TextureHost(TextureFlags aFlags);
+  explicit TextureHost(TextureFlags aFlags);
 
 protected:
   virtual ~TextureHost();
@@ -652,7 +652,7 @@ protected:
 class MOZ_STACK_CLASS AutoLockTextureHost
 {
 public:
-  AutoLockTextureHost(TextureHost* aTexture)
+  explicit AutoLockTextureHost(TextureHost* aTexture)
     : mTexture(aTexture)
   {
     mLocked = mTexture ? mTexture->Lock() : false;
@@ -679,7 +679,7 @@ private:
 class CompositingRenderTarget : public TextureSource
 {
 public:
-  CompositingRenderTarget(const gfx::IntPoint& aOrigin)
+  explicit CompositingRenderTarget(const gfx::IntPoint& aOrigin)
     : mOrigin(aOrigin)
   {}
   virtual ~CompositingRenderTarget() {}
diff --git a/gfx/layers/composite/ThebesLayerComposite.h b/gfx/layers/composite/ThebesLayerComposite.h
index 0a09112cf82a..5d64fbc4c863 100644
--- a/gfx/layers/composite/ThebesLayerComposite.h
+++ b/gfx/layers/composite/ThebesLayerComposite.h
@@ -37,7 +37,7 @@ class ThebesLayerComposite : public ThebesLayer,
                              public LayerComposite
 {
 public:
-  ThebesLayerComposite(LayerManagerComposite *aManager);
+  explicit ThebesLayerComposite(LayerManagerComposite *aManager);
 
 protected:
   virtual ~ThebesLayerComposite();
diff --git a/gfx/layers/composite/TiledContentHost.h b/gfx/layers/composite/TiledContentHost.h
index 1c29651a4551..dfeb45070272 100644
--- a/gfx/layers/composite/TiledContentHost.h
+++ b/gfx/layers/composite/TiledContentHost.h
@@ -189,7 +189,7 @@ class TiledContentHost : public ContentHost,
                          public TiledLayerComposer
 {
 public:
-  TiledContentHost(const TextureInfo& aTextureInfo);
+  explicit TiledContentHost(const TextureInfo& aTextureInfo);
 
 protected:
   ~TiledContentHost();
diff --git a/gfx/layers/ipc/AsyncTransactionTracker.h b/gfx/layers/ipc/AsyncTransactionTracker.h
index 5fb6cd6eebd0..8ea40e58b7f1 100644
--- a/gfx/layers/ipc/AsyncTransactionTracker.h
+++ b/gfx/layers/ipc/AsyncTransactionTracker.h
@@ -190,7 +190,7 @@ protected:
  */
 class FenceDeliveryTracker : public AsyncTransactionTracker {
 public:
-  FenceDeliveryTracker(FenceHandle& aFenceHandle)
+  explicit FenceDeliveryTracker(FenceHandle& aFenceHandle)
     : mFenceHandle(aFenceHandle)
   {
     MOZ_COUNT_CTOR(FenceDeliveryTracker);
diff --git a/gfx/layers/ipc/CompositorChild.h b/gfx/layers/ipc/CompositorChild.h
index 602d44bcbd61..e4d091caaa46 100644
--- a/gfx/layers/ipc/CompositorChild.h
+++ b/gfx/layers/ipc/CompositorChild.h
@@ -41,7 +41,7 @@ class CompositorChild MOZ_FINAL : public PCompositorChild
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING_WITH_MAIN_THREAD_DESTRUCTION(CompositorChild)
 
 public:
-  CompositorChild(ClientLayerManager *aLayerManager);
+  explicit CompositorChild(ClientLayerManager *aLayerManager);
 
   void Destroy();
 
diff --git a/gfx/layers/ipc/CompositorParent.h b/gfx/layers/ipc/CompositorParent.h
index 5bbaa2d1dd95..2dc7e73efe40 100644
--- a/gfx/layers/ipc/CompositorParent.h
+++ b/gfx/layers/ipc/CompositorParent.h
@@ -93,9 +93,9 @@ class CompositorParent : public PCompositorParent,
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING_WITH_MAIN_THREAD_DESTRUCTION(CompositorParent)
 
 public:
-  CompositorParent(nsIWidget* aWidget,
-                   bool aUseExternalSurfaceSize = false,
-                   int aSurfaceWidth = -1, int aSurfaceHeight = -1);
+  explicit CompositorParent(nsIWidget* aWidget,
+                            bool aUseExternalSurfaceSize = false,
+                            int aSurfaceWidth = -1, int aSurfaceHeight = -1);
 
   // IToplevelProtocol::CloneToplevel()
   virtual IToplevelProtocol*
diff --git a/gfx/layers/ipc/FenceUtils.h b/gfx/layers/ipc/FenceUtils.h
index 63f58436ea58..82c2498aaf54 100644
--- a/gfx/layers/ipc/FenceUtils.h
+++ b/gfx/layers/ipc/FenceUtils.h
@@ -23,14 +23,14 @@ struct FenceHandleFromChild;
 
 struct FenceHandle {
   FenceHandle() {}
-  FenceHandle(const FenceHandleFromChild& aFenceHandle) {}
+  explicit FenceHandle(const FenceHandleFromChild& aFenceHandle) {}
   bool operator==(const FenceHandle&) const { return false; }
   bool IsValid() const { return false; }
 };
 
 struct FenceHandleFromChild {
   FenceHandleFromChild() {}
-  FenceHandleFromChild(const FenceHandle& aFence) {}
+  explicit FenceHandleFromChild(const FenceHandle& aFence) {}
   bool operator==(const FenceHandle&) const { return false; }
   bool operator==(const FenceHandleFromChild&) const { return false; }
   bool IsValid() const { return false; }
diff --git a/gfx/layers/ipc/ImageBridgeChild.cpp b/gfx/layers/ipc/ImageBridgeChild.cpp
index a2172c537dba..85cc57696768 100644
--- a/gfx/layers/ipc/ImageBridgeChild.cpp
+++ b/gfx/layers/ipc/ImageBridgeChild.cpp
@@ -101,7 +101,7 @@ struct CompositableTransaction
 };
 
 struct AutoEndTransaction {
-  AutoEndTransaction(CompositableTransaction* aTxn) : mTxn(aTxn) {}
+  explicit AutoEndTransaction(CompositableTransaction* aTxn) : mTxn(aTxn) {}
   ~AutoEndTransaction() { mTxn->End(); }
   CompositableTransaction* mTxn;
 };
@@ -464,7 +464,7 @@ ImageBridgeChild::BeginTransaction()
 class MOZ_STACK_CLASS AutoRemoveTextures
 {
 public:
-  AutoRemoveTextures(ImageBridgeChild* aImageBridge)
+  explicit AutoRemoveTextures(ImageBridgeChild* aImageBridge)
     : mImageBridge(aImageBridge) {}
 
   ~AutoRemoveTextures()
diff --git a/gfx/layers/ipc/ShadowLayerChild.h b/gfx/layers/ipc/ShadowLayerChild.h
index 71b36931ed57..ea7317a08d4e 100644
--- a/gfx/layers/ipc/ShadowLayerChild.h
+++ b/gfx/layers/ipc/ShadowLayerChild.h
@@ -20,7 +20,7 @@ class ShadowableLayer;
 class ShadowLayerChild : public PLayerChild
 {
 public:
-  ShadowLayerChild(ShadowableLayer* aLayer);
+  explicit ShadowLayerChild(ShadowableLayer* aLayer);
   virtual ~ShadowLayerChild();
 
   ShadowableLayer* layer() const { return mLayer; }
diff --git a/gfx/layers/ipc/ShadowLayers.cpp b/gfx/layers/ipc/ShadowLayers.cpp
index c9a15a4287cc..166660f6eba8 100644
--- a/gfx/layers/ipc/ShadowLayers.cpp
+++ b/gfx/layers/ipc/ShadowLayers.cpp
@@ -154,7 +154,7 @@ private:
   Transaction& operator=(const Transaction&);
 };
 struct AutoTxnEnd {
-  AutoTxnEnd(Transaction* aTxn) : mTxn(aTxn) {}
+  explicit AutoTxnEnd(Transaction* aTxn) : mTxn(aTxn) {}
   ~AutoTxnEnd() { mTxn->End(); }
   Transaction* mTxn;
 };
diff --git a/gfx/layers/ipc/SharedBufferManagerParent.cpp b/gfx/layers/ipc/SharedBufferManagerParent.cpp
index d1a3e022be93..69c2e1a9a32b 100644
--- a/gfx/layers/ipc/SharedBufferManagerParent.cpp
+++ b/gfx/layers/ipc/SharedBufferManagerParent.cpp
@@ -108,7 +108,7 @@ void InitGralloc() {
 class DeleteSharedBufferManagerParentTask : public Task
 {
 public:
-    DeleteSharedBufferManagerParentTask(UniquePtr<SharedBufferManagerParent> aSharedBufferManager)
+    explicit DeleteSharedBufferManagerParentTask(UniquePtr<SharedBufferManagerParent> aSharedBufferManager)
         : mSharedBufferManager(Move(aSharedBufferManager)) {
     }
     virtual void Run() MOZ_OVERRIDE {}
diff --git a/gfx/layers/ipc/SharedPlanarYCbCrImage.h b/gfx/layers/ipc/SharedPlanarYCbCrImage.h
index 23f03a3a4147..483e40c1c586 100644
--- a/gfx/layers/ipc/SharedPlanarYCbCrImage.h
+++ b/gfx/layers/ipc/SharedPlanarYCbCrImage.h
@@ -28,7 +28,7 @@ class SharedPlanarYCbCrImage : public PlanarYCbCrImage
                              , public ISharedImage
 {
 public:
-  SharedPlanarYCbCrImage(ImageClient* aCompositable);
+  explicit SharedPlanarYCbCrImage(ImageClient* aCompositable);
 
 protected:
   ~SharedPlanarYCbCrImage();
diff --git a/gfx/layers/ipc/SharedRGBImage.h b/gfx/layers/ipc/SharedRGBImage.h
index 69a919389220..e9aee420d375 100644
--- a/gfx/layers/ipc/SharedRGBImage.h
+++ b/gfx/layers/ipc/SharedRGBImage.h
@@ -40,7 +40,7 @@ class SharedRGBImage : public Image
                      , public ISharedImage
 {
 public:
-  SharedRGBImage(ImageClient* aCompositable);
+  explicit SharedRGBImage(ImageClient* aCompositable);
 
 protected:
   ~SharedRGBImage();
diff --git a/gfx/layers/opengl/CompositorOGL.h b/gfx/layers/opengl/CompositorOGL.h
index 4e959c06fa67..d858fa004533 100644
--- a/gfx/layers/opengl/CompositorOGL.h
+++ b/gfx/layers/opengl/CompositorOGL.h
@@ -85,7 +85,7 @@ public:
 class PerUnitTexturePoolOGL : public CompositorTexturePoolOGL
 {
 public:
-  PerUnitTexturePoolOGL(gl::GLContext* aGL)
+  explicit PerUnitTexturePoolOGL(gl::GLContext* aGL)
   : mTextureTarget(0) // zero is never a valid texture target
   , mGL(aGL)
   {}
@@ -124,7 +124,7 @@ protected:
 class PerFrameTexturePoolOGL : public CompositorTexturePoolOGL
 {
 public:
-  PerFrameTexturePoolOGL(gl::GLContext* aGL)
+  explicit PerFrameTexturePoolOGL(gl::GLContext* aGL)
   : mTextureTarget(0) // zero is never a valid texture target
   , mGL(aGL)
   {}
@@ -162,8 +162,8 @@ class CompositorOGL MOZ_FINAL : public Compositor
 
   std::map<ShaderConfigOGL, ShaderProgramOGL*> mPrograms;
 public:
-  CompositorOGL(nsIWidget *aWidget, int aSurfaceWidth = -1, int aSurfaceHeight = -1,
-                bool aUseExternalSurfaceSize = false);
+  explicit CompositorOGL(nsIWidget *aWidget, int aSurfaceWidth = -1, int aSurfaceHeight = -1,
+                         bool aUseExternalSurfaceSize = false);
 
 protected:
   virtual ~CompositorOGL();
diff --git a/gfx/layers/opengl/GLManager.cpp b/gfx/layers/opengl/GLManager.cpp
index 803aa4f18f5b..a1bd66af69b6 100644
--- a/gfx/layers/opengl/GLManager.cpp
+++ b/gfx/layers/opengl/GLManager.cpp
@@ -23,7 +23,7 @@ namespace layers {
 class GLManagerCompositor : public GLManager
 {
 public:
-  GLManagerCompositor(CompositorOGL* aCompositor)
+  explicit GLManagerCompositor(CompositorOGL* aCompositor)
     : mImpl(aCompositor)
   {}
 
diff --git a/gfx/layers/opengl/MacIOSurfaceTextureClientOGL.h b/gfx/layers/opengl/MacIOSurfaceTextureClientOGL.h
index db838bd491c4..b7353464337a 100644
--- a/gfx/layers/opengl/MacIOSurfaceTextureClientOGL.h
+++ b/gfx/layers/opengl/MacIOSurfaceTextureClientOGL.h
@@ -16,7 +16,7 @@ namespace layers {
 class MacIOSurfaceTextureClientOGL : public TextureClient
 {
 public:
-  MacIOSurfaceTextureClientOGL(TextureFlags aFlags);
+  explicit MacIOSurfaceTextureClientOGL(TextureFlags aFlags);
 
   virtual ~MacIOSurfaceTextureClientOGL();
 
diff --git a/gfx/layers/opengl/TextureClientOGL.h b/gfx/layers/opengl/TextureClientOGL.h
index f506854fea2c..97436ef52745 100644
--- a/gfx/layers/opengl/TextureClientOGL.h
+++ b/gfx/layers/opengl/TextureClientOGL.h
@@ -32,7 +32,7 @@ class CompositableForwarder;
 class SharedTextureClientOGL : public TextureClient
 {
 public:
-  SharedTextureClientOGL(TextureFlags aFlags);
+  explicit SharedTextureClientOGL(TextureFlags aFlags);
 
   ~SharedTextureClientOGL();
 
diff --git a/gfx/layers/opengl/TextureHostOGL.h b/gfx/layers/opengl/TextureHostOGL.h
index b9398ee77727..afaaab398454 100644
--- a/gfx/layers/opengl/TextureHostOGL.h
+++ b/gfx/layers/opengl/TextureHostOGL.h
@@ -212,8 +212,8 @@ class TextureImageTextureSourceOGL : public DataTextureSource
                                    , public BigImageIterator
 {
 public:
-  TextureImageTextureSourceOGL(gl::GLContext* aGL,
-                               TextureFlags aFlags = TextureFlags::DEFAULT)
+  explicit TextureImageTextureSourceOGL(gl::GLContext* aGL,
+                                        TextureFlags aFlags = TextureFlags::DEFAULT)
     : mGL(aGL)
     , mFlags(aFlags)
     , mIterating(false)