Bug 1477471 - Implement PushLayerWithBlend for DrawTargetTiled. r=jrmuizel

gfx/2d/DrawTargetTiled.cpp

@@ -347,6 +347,29 @@ DrawTargetTiled::PushLayer(bool aOpaque, Float aOpacity, SourceSurface* aMask,
   SetPermitSubpixelAA(aOpaque);
 }
 
+void
+DrawTargetTiled::PushLayerWithBlend(bool aOpaque, Float aOpacity,
+                                    SourceSurface* aMask,
+                                    const Matrix& aMaskTransform,
+                                    const IntRect& aBounds,
+                                    bool aCopyBackground,
+                                    CompositionOp aOp)
+{
+  // XXX - not sure this is what we want or whether we want to continue drawing to a larger
+  // intermediate surface, that would require tweaking the code in here a little though.
+  for (size_t i = 0; i < mTiles.size(); i++) {
+    if (!mTiles[i].mClippedOut) {
+      IntRect bounds = aBounds;
+      bounds.MoveBy(-mTiles[i].mTileOrigin);
+      mTiles[i].mDrawTarget->PushLayerWithBlend(aOpaque, aOpacity, aMask, aMaskTransform, bounds, aCopyBackground, aOp);
+    }
+  }
+
+  PushedLayer layer(GetPermitSubpixelAA());
+  mPushedLayers.push_back(layer);
+  SetPermitSubpixelAA(aOpaque);
+}
+
 void
 DrawTargetTiled::PopLayer()
 {

gfx/2d/DrawTargetTiled.h

@@ -116,6 +116,12 @@ public:
                          const Matrix& aMaskTransform,
                          const IntRect& aBounds = IntRect(),
                          bool aCopyBackground = false) override;
+  virtual void PushLayerWithBlend(bool aOpaque, Float aOpacity,
+                         SourceSurface* aMask,
+                         const Matrix& aMaskTransform,
+                         const IntRect& aBounds = IntRect(),
+                         bool aCopyBackground = false,
+                         CompositionOp = CompositionOp::OP_OVER) override;
   virtual void PopLayer() override;