Bug 1360717 - Make WebRenderCompositableHolder could generate WrImageKey r=nical

gfx/layers/ipc/CompositorBridgeParent.cpp

@@ -1612,7 +1612,8 @@ CompositorBridgeParent::AllocPWebRenderBridgeParent(const wr::PipelineId& aPipel
   RefPtr<widget::CompositorWidget> widget = mWidget;
   RefPtr<wr::WebRenderAPI> api = wr::WebRenderAPI::Create(
     gfxPrefs::WebRenderProfilerEnabled(), this, Move(widget), aSize);
-  RefPtr<WebRenderCompositableHolder> holder = new WebRenderCompositableHolder();
+  RefPtr<WebRenderCompositableHolder> holder =
+    new WebRenderCompositableHolder(WebRenderBridgeParent::AllocIdNameSpace());
   MOZ_ASSERT(api); // TODO have a fallback
   api->SetRootPipeline(aPipelineId);
   mWrBridge = new WebRenderBridgeParent(this, aPipelineId, mWidget, nullptr, Move(api), Move(holder));

gfx/layers/wr/WebRenderBridgeParent.cpp

@@ -119,7 +119,7 @@ WebRenderBridgeParent::WebRenderBridgeParent(CompositorBridgeParentBase* aCompos
   , mChildLayerObserverEpoch(0)
   , mParentLayerObserverEpoch(0)
   , mWrEpoch(0)
-  , mIdNameSpace(++sIdNameSpace)
+  , mIdNameSpace(AllocIdNameSpace())
   , mPaused(false)
   , mDestroyed(false)
 {

gfx/layers/wr/WebRenderBridgeParent.h

@@ -165,6 +165,10 @@ public:
   void UpdateAPZ();
   const WebRenderScrollData& GetScrollData() const;
 
+  static uint32_t AllocIdNameSpace() {
+    return ++sIdNameSpace;
+  }
+
 private:
   virtual ~WebRenderBridgeParent();
 

gfx/layers/wr/WebRenderCompositableHolder.cpp

@@ -15,7 +15,9 @@ using namespace gfx;
 
 namespace layers {
 
-WebRenderCompositableHolder::WebRenderCompositableHolder()
+WebRenderCompositableHolder::WebRenderCompositableHolder(uint32_t aIdNamespace)
+ : mIdNamespace(aIdNamespace)
+ , mResourceId(0)
 {
   MOZ_COUNT_CTOR(WebRenderCompositableHolder);
 }

gfx/layers/wr/WebRenderCompositableHolder.h

@@ -28,7 +28,7 @@ class WebRenderCompositableHolder final
 public:
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(WebRenderCompositableHolder)
 
-  explicit WebRenderCompositableHolder();
+  explicit WebRenderCompositableHolder(uint32_t aIdNamespace);
 
 protected:
   ~WebRenderCompositableHolder();
@@ -59,6 +59,16 @@ public:
     return mCompositeUntilTime;
   }
 
+  uint32_t GetNextResourceId() { return ++mResourceId; }
+  uint32_t GetNamespace() { return mIdNamespace; }
+  WrImageKey GetImageKey()
+  {
+    WrImageKey key;
+    key.mNamespace = GetNamespace();
+    key.mHandle = GetNextResourceId();
+    return key;
+  }
+
 private:
 
   struct ForwardingTextureHost {
@@ -75,6 +85,8 @@ private:
     std::queue<ForwardingTextureHost> mTextureHosts;
   };
 
+  uint32_t mIdNamespace;
+  uint32_t mResourceId;
   nsClassHashtable<nsUint64HashKey, PipelineTexturesHolder> mPipelineTexturesHolders;
 
   // Render time for the current composition.