Bug 894405 - Ref GLContext before sending SurfaceStream to compositor r=jgilbert

gfx/gl/GLScreenBuffer.cpp

@@ -58,6 +58,7 @@ GLScreenBuffer::Create(GLContext* gl,
     SurfaceStream* stream = SurfaceStream::CreateForType(
         SurfaceStream::ChooseGLStreamType(SurfaceStream::MainThread,
                                           caps.preserve),
+        gl,
         nullptr);
 
     return new GLScreenBuffer(gl, caps, factory, stream);
@@ -364,7 +365,7 @@ GLScreenBuffer::Morph(SurfaceFactory_GL* newFactory, SurfaceStreamType streamTyp
     if (mStream->mType == streamType)
         return;
 
-    SurfaceStream* newStream = SurfaceStream::CreateForType(streamType, mStream);
+    SurfaceStream* newStream = SurfaceStream::CreateForType(streamType, mGL, mStream);
     MOZ_ASSERT(newStream);
 
     delete mStream;

gfx/gl/SurfaceStream.cpp

@@ -31,20 +31,29 @@ SurfaceStream::ChooseGLStreamType(SurfaceStream::OMTC omtc,
 }
 
 SurfaceStream*
-SurfaceStream::CreateForType(SurfaceStreamType type, SurfaceStream* prevStream)
+SurfaceStream::CreateForType(SurfaceStreamType type, mozilla::gl::GLContext* glContext, SurfaceStream* prevStream)
 {
+    SurfaceStream* result = nullptr;
+
     switch (type) {
         case SurfaceStreamType::SingleBuffer:
-            return new SurfaceStream_SingleBuffer(prevStream);
+            result = new SurfaceStream_SingleBuffer(prevStream);
+            break;
         case SurfaceStreamType::TripleBuffer_Copy:
-            return new SurfaceStream_TripleBuffer_Copy(prevStream);
+            result = new SurfaceStream_TripleBuffer_Copy(prevStream);
+            break;
         case SurfaceStreamType::TripleBuffer_Async:
-            return new SurfaceStream_TripleBuffer_Async(prevStream);
+            result = new SurfaceStream_TripleBuffer_Async(prevStream);
+            break;
         case SurfaceStreamType::TripleBuffer:
-            return new SurfaceStream_TripleBuffer(prevStream);
+            result = new SurfaceStream_TripleBuffer(prevStream);
+            break;
         default:
             MOZ_CRASH("Invalid Type.");
     }
+
+    result->mGLContext = glContext;
+    return result;
 }
 
 void

gfx/gl/SurfaceStream.h

@@ -12,6 +12,7 @@
 #include "mozilla/Attributes.h"
 #include "gfxPoint.h"
 #include "SurfaceTypes.h"
+#include "GLContext.h"
 
 namespace mozilla {
 namespace gfx {
@@ -31,6 +32,7 @@ public:
                                                 bool preserveBuffer);
 
     static SurfaceStream* CreateForType(SurfaceStreamType type,
+                                        mozilla::gl::GLContext* glContext,
                                         SurfaceStream* prevStream = nullptr);
 
     SurfaceStreamHandle GetShareHandle() {
@@ -42,6 +44,8 @@ public:
     }
 
     const SurfaceStreamType mType;
+
+    mozilla::gl::GLContext* GLContext() const { return mGLContext; }
 protected:
     // |mProd| is owned by us, but can be ripped away when
     // creating a new GLStream from this one.
@@ -51,6 +55,10 @@ protected:
     mutable Monitor mMonitor;
     bool mIsAlive;
 
+    // Do not use this. It exists solely so we can ref it in CanvasClientWebGL::Update()
+    // before sent up to the compositor. You have been warned (Bug 894405)
+    mozilla::gl::GLContext* mGLContext;
+
     // |previous| can be null, indicating this is the first one.
     // Otherwise, we pull in |mProd| from |previous| an our initial surface.
     SurfaceStream(SurfaceStreamType type, SurfaceStream* prevStream)

gfx/layers/client/CanvasClient.cpp

@@ -125,6 +125,12 @@ CanvasClientWebGL::Update(gfx::IntSize aSize, ClientCanvasLayer* aLayer)
   } else {
     SurfaceStreamHandle handle = stream->GetShareHandle();
     mDeprecatedTextureClient->SetDescriptor(SurfaceStreamDescriptor(handle, false));
+
+    // Bug 894405
+    //
+    // Ref this so the SurfaceStream doesn't disappear unexpectedly. The
+    // Compositor will need to unref it when finished.
+    aLayer->mGLContext->AddRef();
   }
 
   aLayer->Painted();

gfx/layers/opengl/TextureHostOGL.cpp

@@ -922,6 +922,28 @@ SurfaceStreamHostOGL::GetAsSurface() {
   return surf.forget();
 }
 
+void
+SurfaceStreamHostOGL::SetBuffer(SurfaceDescriptor* aBuffer, ISurfaceAllocator* aAllocator)
+{
+  MOZ_ASSERT(!mBuffer, "Will leak the old mBuffer");
+  mBuffer = aBuffer;
+  mDeAllocator = aAllocator;
+
+  if (mBuffer && mBuffer->type() == SurfaceDescriptor::TSurfaceStreamDescriptor) {
+    // Bug 894405
+    //
+    // The SurfaceStream's GLContext was refed before being passed up to us, so
+    // we need to ensure it gets unrefed when we are finished.
+    const SurfaceStreamDescriptor& streamDesc =
+        mBuffer->get_SurfaceStreamDescriptor();
+
+    SurfaceStream* surfStream = SurfaceStream::FromHandle(streamDesc.handle());
+    if (surfStream) {
+      mStreamGL = dont_AddRef(surfStream->GLContext());
+    }
+  } 
+}
+
 already_AddRefed<gfxImageSurface>
 TiledDeprecatedTextureHostOGL::GetAsSurface() {
   nsRefPtr<gfxImageSurface> surf = IsValid() ?

gfx/layers/opengl/TextureHostOGL.h

@@ -485,6 +485,8 @@ public:
 
   virtual already_AddRefed<gfxImageSurface> GetAsSurface() MOZ_OVERRIDE;
 
+  virtual void SetBuffer(SurfaceDescriptor* aBuffer, ISurfaceAllocator* aAllocator) MOZ_OVERRIDE;
+
 #ifdef MOZ_LAYERS_HAVE_LOG
   virtual const char* Name() { return "SurfaceStreamHostOGL"; }
 #endif
@@ -506,6 +508,7 @@ protected:
   GLenum mTextureTarget;
   GLuint mUploadTexture;
   GLenum mWrapMode;
+  nsRefPtr<GLContext> mStreamGL;
 };
 
 class TiledDeprecatedTextureHostOGL : public DeprecatedTextureHost