Bug 893301. Content clients. r=nical

gfx/layers/CompositorTypes.h

@@ -64,6 +64,12 @@ const TextureFlags TEXTURE_COPY_PREVIOUS      = 1 << 24;
 // deallocation.
 // The default behaviour is to deallocate on the host side.
 const TextureFlags TEXTURE_DEALLOCATE_CLIENT  = 1 << 25;
+// The host side is responsible for deallocation, but that may not happen
+// immediately after the client side requests it. Exactly when the texture is
+// deallocated is up to the compositable. The texture must be deallocated by
+// the time the compositable or texture host is destroyed. A texture may not
+// have both TEXTURE_DEALLOCATE_CLIENT and TEXTURE_DEALLOCATE_DEFERRED flags.
+const TextureFlags TEXTURE_DEALLOCATE_DEFERRED  = 1 << 26;
 // After being shared ith the compositor side, an immutable texture is never
 // modified, it can only be read. It is safe to not Lock/Unlock immutable
 // textures.
@@ -76,6 +82,9 @@ const TextureFlags TEXTURE_IMMEDIATE_UPLOAD   = 1 << 28;
 // buffered pair, and so we can guarantee that the producer/consumer
 // won't be racing to access its contents.
 const TextureFlags TEXTURE_DOUBLE_BUFFERED    = 1 << 29;
+// We've previously tried a texture and it didn't work for some reason. If there
+// is a fallback available, try that.
+const TextureFlags TEXTURE_ALLOC_FALLBACK     = 1 << 31;
 
 // the default flags
 const TextureFlags TEXTURE_FLAGS_DEFAULT = TEXTURE_FRONT;
@@ -167,6 +176,8 @@ enum CompositableType
   BUFFER_TILED,           // tiled thebes layer
   // the new compositable types
   COMPOSITABLE_IMAGE,     // image with single buffering
+  COMPOSITABLE_CONTENT_SINGLE,  // thebes layer interface, single buffering
+  COMPOSITABLE_CONTENT_DOUBLE,  // thebes layer interface, double buffering
   BUFFER_COUNT
 };
 

gfx/layers/client/ClientThebesLayer.cpp

@@ -106,6 +106,18 @@ ClientThebesLayer::RenderLayer()
   mContentClient->BeginPaint();
   PaintThebes();
   mContentClient->EndPaint();
+  // It is very important that this is called after EndPaint, because destroying
+  // textures is a three stage process:
+  // 1. We are done with the buffer and move it to ContentClient::mOldTextures,
+  // that happens in DestroyBuffers which is may be called indirectly from
+  // PaintThebes.
+  // 2. The content client calls RemoveTextureClient on the texture clients in
+  // mOldTextures and forgets them. They then become invalid. The compositable
+  // client keeps a record of IDs. This happens in EndPaint.
+  // 3. An IPC message is sent to destroy the corresponding texture host. That
+  // happens from OnTransaction.
+  // It is important that these steps happen in order.
+  mContentClient->OnTransaction();
 }
 
 void

gfx/layers/client/ContentClient.cpp

@@ -62,15 +62,22 @@ ContentClient::CreateContentClient(CompositableForwarder* aForwarder)
   }
 
   if (useDoubleBuffering || PR_GetEnv("MOZ_FORCE_DOUBLE_BUFFERING")) {
-    return new ContentClientDoubleBuffered(aForwarder);
+    if (gfxPlatform::GetPlatform()->UseDeprecatedTextures()) {
+      return new ContentClientDoubleBuffered(aForwarder);
+    } else {
+      return new ContentClientDoubleBufferedNew(aForwarder);
+    }
   }
 #ifdef XP_MACOSX
   if (backend == LAYERS_OPENGL) {
     return new ContentClientIncremental(aForwarder);
   }
 #endif
-  return new ContentClientSingleBuffered(aForwarder);
-
+  if (gfxPlatform::GetPlatform()->UseDeprecatedTextures()) {
+    return new ContentClientSingleBuffered(aForwarder);
+  } else {
+    return new ContentClientSingleBufferedNew(aForwarder);
+  }
 }
 
 ContentClientBasic::ContentClientBasic(CompositableForwarder* aForwarder,
@@ -97,6 +104,206 @@ ContentClientBasic::CreateBuffer(ContentType aType,
     ImageFormatToSurfaceFormat(format));
 }
 
+void
+ContentClientRemoteBufferNew::DestroyBuffers()
+{
+  if (!mTextureClient) {
+    return;
+  }
+  MOZ_ASSERT(mTextureClient->GetAccessMode() == TextureClient::ACCESS_READ_WRITE);
+
+  mOldTextures.AppendElement(mTextureClient);
+  mTextureClient = nullptr;
+  if (mTextureClientOnWhite) {
+    mOldTextures.AppendElement(mTextureClientOnWhite);
+    mTextureClientOnWhite = nullptr;
+  }
+
+  DestroyFrontBuffer();
+}
+
+void
+ContentClientRemoteBufferNew::BeginPaint()
+{
+  // XXX: So we might not have a DeprecatedTextureClient yet.. because it will
+  // only be created by CreateBuffer.. which will deliver a locked surface!.
+  if (mTextureClient) {
+    SetNewBufferProvider(mTextureClient);
+  }
+  if (mTextureClientOnWhite) {
+    SetNewBufferProviderOnWhite(mTextureClientOnWhite);
+  }
+}
+
+void
+ContentClientRemoteBufferNew::EndPaint()
+{
+  // XXX: We might still not have a texture client if PaintThebes
+  // decided we didn't need one yet because the region to draw was empty.
+  SetNewBufferProvider(nullptr);
+  SetNewBufferProviderOnWhite(nullptr);
+  for (size_t i = 0; i < mOldTextures.Length(); ++i) {
+    RemoveTextureClient(mOldTextures[i]);
+  }
+  mOldTextures.Clear();
+
+  if (mTextureClient) {
+    mTextureClient->Unlock();
+  }
+  if (mTextureClientOnWhite) {
+    mTextureClientOnWhite->Unlock();
+  }
+}
+
+bool
+ContentClientRemoteBufferNew::CreateAndAllocateTextureClient(RefPtr<TextureClient>& aClient,
+                                                             TextureFlags aFlags)
+{
+  aClient = CreateTextureClientForDrawing(mSurfaceFormat,
+                                          mTextureInfo.mTextureFlags | aFlags);
+  if (!aClient) {
+    return false;
+  }
+
+  if (!aClient->AsTextureClientDrawTarget()->AllocateForSurface(mSize)) {
+    aClient = CreateTextureClientForDrawing(mSurfaceFormat,
+                mTextureInfo.mTextureFlags | TEXTURE_ALLOC_FALLBACK | aFlags);
+    if (!aClient) {
+      return false;
+    }
+    if (!aClient->AsTextureClientDrawTarget()->AllocateForSurface(mSize)) {
+      NS_WARNING("Could not allocate texture client");
+      aClient = nullptr;
+      return false;
+    }
+  }
+
+  NS_WARN_IF_FALSE(aClient->IsValid(), "Created an invalid texture client");
+  return true;
+}
+
+void
+ContentClientRemoteBufferNew::BuildTextureClients(SurfaceFormat aFormat,
+                                                  const nsIntRect& aRect,
+                                                  uint32_t aFlags)
+{
+  // If we hit this assertion, then it might be due to an empty transaction
+  // followed by a real transaction. Our buffers should be created (but not
+  // painted in the empty transaction) and then painted (but not created) in the
+  // real transaction. That is kind of fragile, and this assert will catch
+  // circumstances where we screw that up, e.g., by unnecessarily recreating our
+  // buffers.
+  NS_ABORT_IF_FALSE(!mIsNewBuffer,
+                    "Bad! Did we create a buffer twice without painting?");
+
+  mIsNewBuffer = true;
+
+  DestroyBuffers();
+
+  mSurfaceFormat = aFormat;
+  mSize = gfx::IntSize(aRect.width, aRect.height);
+  mTextureInfo.mTextureFlags = (aFlags & ~TEXTURE_DEALLOCATE_CLIENT) |
+                               TEXTURE_DEALLOCATE_DEFERRED;
+
+  if (!CreateAndAllocateTextureClient(mTextureClient, TEXTURE_ON_BLACK) ||
+      !AddTextureClient(mTextureClient)) {
+    AbortTextureClientCreation();
+    return;
+  }
+
+  if (aFlags & BUFFER_COMPONENT_ALPHA) {
+    if (!CreateAndAllocateTextureClient(mTextureClientOnWhite, TEXTURE_ON_WHITE) ||
+        !AddTextureClient(mTextureClientOnWhite)) {
+      AbortTextureClientCreation();
+      return;
+    }
+    mTextureInfo.mTextureFlags |= TEXTURE_COMPONENT_ALPHA;
+  }
+
+  CreateFrontBuffer(aRect);
+}
+
+void
+ContentClientRemoteBufferNew::CreateBuffer(ContentType aType,
+                                        const nsIntRect& aRect,
+                                        uint32_t aFlags,
+                                        RefPtr<gfx::DrawTarget>* aBlackDT,
+                                        RefPtr<gfx::DrawTarget>* aWhiteDT)
+{
+  BuildTextureClients(gfxPlatform::GetPlatform()->Optimal2DFormatForContent(aType), aRect, aFlags);
+  if (!mTextureClient) {
+    return;
+  }
+
+  *aBlackDT = mTextureClient->AsTextureClientDrawTarget()->GetAsDrawTarget();
+  if (aFlags & BUFFER_COMPONENT_ALPHA) {
+    *aWhiteDT = mTextureClientOnWhite->AsTextureClientDrawTarget()->GetAsDrawTarget();
+  }
+}
+
+nsIntRegion
+ContentClientRemoteBufferNew::GetUpdatedRegion(const nsIntRegion& aRegionToDraw,
+                                            const nsIntRegion& aVisibleRegion,
+                                            bool aDidSelfCopy)
+{
+  nsIntRegion updatedRegion;
+  if (mIsNewBuffer || aDidSelfCopy) {
+    // A buffer reallocation clears both buffers. The front buffer has all the
+    // content by now, but the back buffer is still clear. Here, in effect, we
+    // are saying to copy all of the pixels of the front buffer to the back.
+    // Also when we self-copied in the buffer, the buffer space
+    // changes and some changed buffer content isn't reflected in the
+    // draw or invalidate region (on purpose!).  When this happens, we
+    // need to read back the entire buffer too.
+    updatedRegion = aVisibleRegion;
+    mIsNewBuffer = false;
+  } else {
+    updatedRegion = aRegionToDraw;
+  }
+
+  NS_ASSERTION(BufferRect().Contains(aRegionToDraw.GetBounds()),
+               "Update outside of buffer rect!");
+  NS_ABORT_IF_FALSE(mTextureClient, "should have a back buffer by now");
+
+  return updatedRegion;
+}
+
+void
+ContentClientRemoteBufferNew::Updated(const nsIntRegion& aRegionToDraw,
+                                   const nsIntRegion& aVisibleRegion,
+                                   bool aDidSelfCopy)
+{
+  nsIntRegion updatedRegion = GetUpdatedRegion(aRegionToDraw,
+                                               aVisibleRegion,
+                                               aDidSelfCopy);
+
+  MOZ_ASSERT(mTextureClient);
+  mTextureClient->SetAccessMode(TextureClient::ACCESS_NONE);
+  if (mTextureClientOnWhite) {
+    mTextureClientOnWhite->SetAccessMode(TextureClient::ACCESS_NONE);
+  }
+  LockFrontBuffer();
+  mForwarder->UseTexture(this, mTextureClient);
+  mForwarder->UpdateTextureRegion(this,
+                                  ThebesBufferData(BufferRect(),
+                                                   BufferRotation()),
+                                  updatedRegion);
+}
+
+void
+ContentClientRemoteBufferNew::SwapBuffers(const nsIntRegion& aFrontUpdatedRegion)
+{
+  MOZ_ASSERT(mTextureClient->GetAccessMode() == TextureClient::ACCESS_NONE);
+  MOZ_ASSERT(!mTextureClientOnWhite || mTextureClientOnWhite->GetAccessMode() == TextureClient::ACCESS_NONE);
+  MOZ_ASSERT(mTextureClient);
+
+  mFrontAndBackBufferDiffer = true;
+  mTextureClient->SetAccessMode(TextureClient::ACCESS_READ_WRITE);
+  if (mTextureClientOnWhite) {
+    mTextureClientOnWhite->SetAccessMode(TextureClient::ACCESS_READ_WRITE);
+  }
+}
+
 void
 ContentClientRemoteBuffer::DestroyBuffers()
 {
@@ -297,6 +504,178 @@ ContentClientRemoteBuffer::OnActorDestroy()
     mOldTextures[i]->OnActorDestroy();
   }
 }
+ 
+void
+ContentClientDoubleBufferedNew::CreateFrontBuffer(const nsIntRect& aBufferRect)
+{
+  if (!CreateAndAllocateTextureClient(mFrontClient, TEXTURE_ON_BLACK) ||
+      !AddTextureClient(mFrontClient)) {
+    AbortTextureClientCreation();
+    return;
+  }
+  if (mTextureInfo.mTextureFlags & TEXTURE_COMPONENT_ALPHA) {
+    if (!CreateAndAllocateTextureClient(mFrontClientOnWhite, TEXTURE_ON_WHITE) ||
+        !AddTextureClient(mFrontClientOnWhite)) {
+      AbortTextureClientCreation();
+      return;
+    }
+  }
+
+  mFrontBufferRect = aBufferRect;
+  mFrontBufferRotation = nsIntPoint();
+}
+
+void
+ContentClientDoubleBufferedNew::DestroyFrontBuffer()
+{
+  MOZ_ASSERT(mFrontClient);
+  MOZ_ASSERT(mFrontClient->GetAccessMode() != TextureClient::ACCESS_NONE);
+
+  mOldTextures.AppendElement(mFrontClient);
+  mFrontClient = nullptr;
+  if (mFrontClientOnWhite) {
+    mOldTextures.AppendElement(mFrontClientOnWhite);
+    mFrontClientOnWhite = nullptr;
+  }
+}
+
+void
+ContentClientDoubleBufferedNew::LockFrontBuffer()
+{
+  MOZ_ASSERT(mFrontClient);
+  mFrontClient->SetAccessMode(TextureClient::ACCESS_NONE);
+  if (mFrontClientOnWhite) {
+    mFrontClientOnWhite->SetAccessMode(TextureClient::ACCESS_NONE);
+  }
+}
+
+void
+ContentClientDoubleBufferedNew::SwapBuffers(const nsIntRegion& aFrontUpdatedRegion)
+{
+  mFrontUpdatedRegion = aFrontUpdatedRegion;
+
+  RefPtr<TextureClient> oldBack = mTextureClient;
+  mTextureClient = mFrontClient;
+  mFrontClient = oldBack;
+
+  oldBack = mTextureClientOnWhite;
+  mTextureClientOnWhite = mFrontClientOnWhite;
+  mFrontClientOnWhite = oldBack;
+
+  nsIntRect oldBufferRect = mBufferRect;
+  mBufferRect = mFrontBufferRect;
+  mFrontBufferRect = oldBufferRect;
+
+  nsIntPoint oldBufferRotation = mBufferRotation;
+  mBufferRotation = mFrontBufferRotation;
+  mFrontBufferRotation = oldBufferRotation;
+
+  MOZ_ASSERT(mFrontClient);
+  mFrontClient->SetAccessMode(TextureClient::ACCESS_READ_ONLY);
+  if (mFrontClientOnWhite) {
+    mFrontClientOnWhite->SetAccessMode(TextureClient::ACCESS_READ_ONLY);
+  }
+
+  ContentClientRemoteBufferNew::SwapBuffers(aFrontUpdatedRegion);
+}
+
+void
+ContentClientDoubleBufferedNew::SyncFrontBufferToBackBuffer()
+{
+  if (!mFrontAndBackBufferDiffer) {
+    return;
+  }
+  MOZ_ASSERT(mFrontClient);
+  MOZ_ASSERT(mFrontClient->GetAccessMode() == TextureClient::ACCESS_READ_ONLY);
+  MOZ_ASSERT(!mFrontClientOnWhite ||
+             mFrontClientOnWhite->GetAccessMode() == TextureClient::ACCESS_READ_ONLY);
+
+  MOZ_LAYERS_LOG(("BasicShadowableThebes(%p): reading back <x=%d,y=%d,w=%d,h=%d>",
+                  this,
+                  mFrontUpdatedRegion.GetBounds().x,
+                  mFrontUpdatedRegion.GetBounds().y,
+                  mFrontUpdatedRegion.GetBounds().width,
+                  mFrontUpdatedRegion.GetBounds().height));
+
+  nsIntRegion updateRegion = mFrontUpdatedRegion;
+
+  // This is a tricky trade off, we're going to get stuff out of our
+  // frontbuffer now, but the next PaintThebes might throw it all (or mostly)
+  // away if the visible region has changed. This is why in reality we want
+  // this code integrated with PaintThebes to always do the optimal thing.
+
+  if (mDidSelfCopy) {
+    mDidSelfCopy = false;
+    // We can't easily draw our front buffer into us, since we're going to be
+    // copying stuff around anyway it's easiest if we just move our situation
+    // to non-rotated while we're at it. If this situation occurs we'll have
+    // hit a self-copy path in PaintThebes before as well anyway.
+    mBufferRect.MoveTo(mFrontBufferRect.TopLeft());
+    mBufferRotation = nsIntPoint();
+    updateRegion = mBufferRect;
+  } else {
+    mBufferRect = mFrontBufferRect;
+    mBufferRotation = mFrontBufferRotation;
+  }
+
+  mIsNewBuffer = false;
+  mFrontAndBackBufferDiffer = false;
+
+  // We need to ensure that we lock these two buffers in the same
+  // order as the compositor to prevent deadlocks.
+  if (!mFrontClient->Lock(OPEN_READ_ONLY)) {
+    return;
+  }
+  if (mFrontClientOnWhite &&
+      !mFrontClientOnWhite->Lock(OPEN_READ_ONLY)) {
+    mFrontClient->Unlock();
+    return;
+  }
+  RefPtr<DrawTarget> dt =
+    mFrontClient->AsTextureClientDrawTarget()->GetAsDrawTarget();
+  RefPtr<DrawTarget> dtOnWhite = mFrontClientOnWhite
+    ? mFrontClientOnWhite->AsTextureClientDrawTarget()->GetAsDrawTarget()
+    : nullptr;
+  RotatedBuffer frontBuffer(dt,
+                            dtOnWhite,
+                            mFrontBufferRect,
+                            mFrontBufferRotation);
+  UpdateDestinationFrom(frontBuffer, updateRegion);
+  mFrontClient->Unlock();
+  if (mFrontClientOnWhite) {
+    mFrontClientOnWhite->Unlock();
+  }
+}
+
+void
+ContentClientDoubleBufferedNew::UpdateDestinationFrom(const RotatedBuffer& aSource,
+                                                   const nsIntRegion& aUpdateRegion)
+{
+  nsRefPtr<gfxContext> destCtx =
+    GetContextForQuadrantUpdate(aUpdateRegion.GetBounds(), BUFFER_BLACK);
+  destCtx->SetOperator(gfxContext::OPERATOR_SOURCE);
+
+  bool isClippingCheap = IsClippingCheap(destCtx, aUpdateRegion);
+  if (isClippingCheap) {
+    gfxUtils::ClipToRegion(destCtx, aUpdateRegion);
+  }
+
+  aSource.DrawBufferWithRotation(destCtx->GetDrawTarget(), BUFFER_BLACK, 1.0, OP_SOURCE);
+
+  if (aSource.HaveBufferOnWhite()) {
+    MOZ_ASSERT(HaveBufferOnWhite());
+    nsRefPtr<gfxContext> destCtx =
+      GetContextForQuadrantUpdate(aUpdateRegion.GetBounds(), BUFFER_WHITE);
+    destCtx->SetOperator(gfxContext::OPERATOR_SOURCE);
+
+    bool isClippingCheap = IsClippingCheap(destCtx, aUpdateRegion);
+    if (isClippingCheap) {
+      gfxUtils::ClipToRegion(destCtx, aUpdateRegion);
+    }
+
+    aSource.DrawBufferWithRotation(destCtx->GetDrawTarget(), BUFFER_WHITE, 1.0, OP_SOURCE);
+  }
+}
 
 ContentClientDoubleBuffered::~ContentClientDoubleBuffered()
 {
@@ -530,6 +909,34 @@ ContentClientDoubleBuffered::UpdateDestinationFrom(const RotatedBuffer& aSource,
   }
 }
 
+void
+ContentClientSingleBufferedNew::SyncFrontBufferToBackBuffer()
+{
+  if (!mFrontAndBackBufferDiffer) {
+    return;
+  }
+
+  RefPtr<DrawTarget> backBuffer = GetDTBuffer();
+  if (!backBuffer && mTextureClient) {
+    backBuffer = mTextureClient->AsTextureClientDrawTarget()->GetAsDrawTarget();
+  }
+
+  RefPtr<DrawTarget> oldBuffer;
+  oldBuffer = SetDTBuffer(backBuffer,
+                          mBufferRect,
+                          mBufferRotation);
+
+  backBuffer = GetDTBufferOnWhite();
+  if (!backBuffer && mTextureClientOnWhite) {
+    backBuffer = mTextureClientOnWhite->AsTextureClientDrawTarget()->GetAsDrawTarget();
+  }
+
+  oldBuffer = SetDTBufferOnWhite(backBuffer);
+
+  mIsNewBuffer = false;
+  mFrontAndBackBufferDiffer = false;
+}
+
 ContentClientSingleBuffered::~ContentClientSingleBuffered()
 {
   if (mDeprecatedTextureClient) {

gfx/layers/client/ContentClient.h

@@ -182,6 +182,109 @@ private:
  * If the size or type of our buffer(s) change(s), then we simply destroy and
  * create them.
  */
+// Version using new texture clients
+class ContentClientRemoteBufferNew : public ContentClientRemote
+                                   , protected RotatedContentBuffer
+{
+  using RotatedContentBuffer::BufferRect;
+  using RotatedContentBuffer::BufferRotation;
+public:
+  ContentClientRemoteBufferNew(CompositableForwarder* aForwarder)
+    : ContentClientRemote(aForwarder)
+    , RotatedContentBuffer(ContainsVisibleBounds)
+    , mIsNewBuffer(false)
+    , mFrontAndBackBufferDiffer(false)
+    , mSurfaceFormat(gfx::FORMAT_B8G8R8A8)
+  {}
+
+  typedef RotatedContentBuffer::PaintState PaintState;
+  typedef RotatedContentBuffer::ContentType ContentType;
+
+  virtual void Clear() { RotatedContentBuffer::Clear(); }
+  PaintState BeginPaintBuffer(ThebesLayer* aLayer, ContentType aContentType,
+                              uint32_t aFlags)
+  {
+    return RotatedContentBuffer::BeginPaint(aLayer, aContentType, aFlags);
+  }
+
+  /**
+   * Begin/End Paint map a gfxASurface from the texture client
+   * into the buffer of RotatedBuffer. The surface is only
+   * valid when the texture client is locked, so is mapped out
+   * of RotatedContentBuffer when we are done painting.
+   * None of the underlying buffer attributes (rect, rotation)
+   * are affected by mapping/unmapping.
+   */
+  virtual void BeginPaint() MOZ_OVERRIDE;
+  virtual void EndPaint() MOZ_OVERRIDE;
+
+  virtual void Updated(const nsIntRegion& aRegionToDraw,
+                       const nsIntRegion& aVisibleRegion,
+                       bool aDidSelfCopy);
+
+  virtual void SwapBuffers(const nsIntRegion& aFrontUpdatedRegion) MOZ_OVERRIDE;
+
+  // Expose these protected methods from the superclass.
+  virtual const nsIntRect& BufferRect() const
+  {
+    return RotatedContentBuffer::BufferRect();
+  }
+  virtual const nsIntPoint& BufferRotation() const
+  {
+    return RotatedContentBuffer::BufferRotation();
+  }
+
+  virtual void CreateBuffer(ContentType aType, const nsIntRect& aRect, uint32_t aFlags,
+                            RefPtr<gfx::DrawTarget>* aBlackDT, RefPtr<gfx::DrawTarget>* aWhiteDT) MOZ_OVERRIDE;
+
+  virtual TextureInfo GetTextureInfo() const MOZ_OVERRIDE
+  {
+    return mTextureInfo;
+  }
+
+protected:
+  void DestroyBuffers();
+
+  virtual nsIntRegion GetUpdatedRegion(const nsIntRegion& aRegionToDraw,
+                                       const nsIntRegion& aVisibleRegion,
+                                       bool aDidSelfCopy);
+
+  void BuildTextureClients(gfx::SurfaceFormat aFormat,
+                           const nsIntRect& aRect,
+                           uint32_t aFlags);
+
+  // Create the front buffer for the ContentClient/Host pair if necessary
+  // and notify the compositor that we have created the buffer(s).
+  virtual void CreateFrontBuffer(const nsIntRect& aBufferRect) = 0;
+  virtual void DestroyFrontBuffer() {}
+  // We're about to hand off to the compositor, if you've got a back buffer,
+  // lock it now.
+  virtual void LockFrontBuffer() {}
+
+  bool CreateAndAllocateTextureClient(RefPtr<TextureClient>& aClient,
+                                      TextureFlags aFlags = 0);
+
+  virtual void AbortTextureClientCreation()
+  {
+    mTextureClient = nullptr;
+    mTextureClientOnWhite = nullptr;
+    mIsNewBuffer = false;
+  }
+
+  RefPtr<TextureClient> mTextureClient;
+  RefPtr<TextureClient> mTextureClientOnWhite;
+  // keep a record of texture clients we have created and need to keep around
+  // (for RotatedBuffer to access), then unlock and remove them when we are done
+  // painting.
+  nsTArray<RefPtr<TextureClient> > mOldTextures;
+
+  TextureInfo mTextureInfo;
+  bool mIsNewBuffer;
+  bool mFrontAndBackBufferDiffer;
+  gfx::IntSize mSize;
+  gfx::SurfaceFormat mSurfaceFormat;
+};
+
 class ContentClientRemoteBuffer : public ContentClientRemote
                                 , protected RotatedContentBuffer
 {
@@ -237,8 +340,6 @@ public:
   virtual void CreateBuffer(ContentType aType, const nsIntRect& aRect, uint32_t aFlags,
                             RefPtr<gfx::DrawTarget>* aBlackDT, RefPtr<gfx::DrawTarget>* aWhiteDT) MOZ_OVERRIDE;
 
-  void DestroyBuffers();
-
   virtual TextureInfo GetTextureInfo() const MOZ_OVERRIDE
   {
     return mTextureInfo;
@@ -247,6 +348,8 @@ public:
   virtual void OnActorDestroy() MOZ_OVERRIDE;
 
 protected:
+  void DestroyBuffers();
+
   virtual nsIntRegion GetUpdatedRegion(const nsIntRegion& aRegionToDraw,
                                        const nsIntRegion& aVisibleRegion,
                                        bool aDidSelfCopy);
@@ -290,6 +393,44 @@ protected:
  * references. In response to the compositor's reply we swap our references
  * (in SwapBuffers).
  */
+class ContentClientDoubleBufferedNew : public ContentClientRemoteBufferNew
+{
+public:
+  ContentClientDoubleBufferedNew(CompositableForwarder* aFwd)
+    : ContentClientRemoteBufferNew(aFwd)
+  {
+    mTextureInfo.mCompositableType = COMPOSITABLE_CONTENT_DOUBLE;
+  }
+  virtual ~ContentClientDoubleBufferedNew() {}
+
+  virtual void SwapBuffers(const nsIntRegion& aFrontUpdatedRegion) MOZ_OVERRIDE;
+
+  virtual void SyncFrontBufferToBackBuffer() MOZ_OVERRIDE;
+
+protected:
+  virtual void CreateFrontBuffer(const nsIntRect& aBufferRect) MOZ_OVERRIDE;
+  virtual void DestroyFrontBuffer() MOZ_OVERRIDE;
+  virtual void LockFrontBuffer() MOZ_OVERRIDE;
+
+private:
+  void UpdateDestinationFrom(const RotatedBuffer& aSource,
+                             const nsIntRegion& aUpdateRegion);
+
+  virtual void AbortTextureClientCreation() MOZ_OVERRIDE
+  {
+    mTextureClient = nullptr;
+    mTextureClientOnWhite = nullptr;
+    mFrontClient = nullptr;
+    mFrontClientOnWhite = nullptr;
+  }
+
+  RefPtr<TextureClient> mFrontClient;
+  RefPtr<TextureClient> mFrontClientOnWhite;
+  nsIntRegion mFrontUpdatedRegion;
+  nsIntRect mFrontBufferRect;
+  nsIntPoint mFrontBufferRotation;
+};
+
 class ContentClientDoubleBuffered : public ContentClientRemoteBuffer
 {
 public:
@@ -330,6 +471,22 @@ private:
  * kind. We are free to modify the TextureClient once we receive reply from
  * the compositor.
  */
+class ContentClientSingleBufferedNew : public ContentClientRemoteBufferNew
+{
+public:
+  ContentClientSingleBufferedNew(CompositableForwarder* aFwd)
+    : ContentClientRemoteBufferNew(aFwd)
+  {
+    mTextureInfo.mCompositableType = COMPOSITABLE_CONTENT_SINGLE;
+  }
+  virtual ~ContentClientSingleBufferedNew() {}
+
+  virtual void SyncFrontBufferToBackBuffer() MOZ_OVERRIDE;
+
+protected:
+  virtual void CreateFrontBuffer(const nsIntRect& aBufferRect) MOZ_OVERRIDE {}
+};
+
 class ContentClientSingleBuffered : public ContentClientRemoteBuffer
 {
 public:

gfx/layers/client/TextureClient.h

@@ -279,6 +279,12 @@ public:
 
   virtual bool AllocateForSurface(gfx::IntSize aSize) MOZ_OVERRIDE;
 
+  // TextureClientDrawTarget
+
+  virtual TextureClientDrawTarget* AsTextureClientDrawTarget() MOZ_OVERRIDE { return this; }
+
+  virtual TemporaryRef<gfx::DrawTarget> GetAsDrawTarget() MOZ_OVERRIDE;
+
   // TextureClientYCbCr
 
   virtual TextureClientYCbCr* AsTextureClientYCbCr() MOZ_OVERRIDE { return this; }
@@ -289,7 +295,7 @@ public:
                                 gfx::IntSize aCbCrSize,
                                 StereoMode aStereoMode) MOZ_OVERRIDE;
 
-  gfx::SurfaceFormat GetFormat() const { return mFormat; }
+  virtual gfx::SurfaceFormat GetFormat() const MOZ_OVERRIDE { return mFormat; }
 
   // XXX - Bug 908196 - Make Allocate(uint32_t) and GetBufferSize() protected.
   // these two methods should only be called by methods of BufferTextureClient