Add effect node support in PaintArtifactCompositor for layer list mode [1/4]

third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositor.h

Index: third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositor.h
diff --git a/third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositor.h b/third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositor.h
index b98d23084242863ce67be6e05e3019d2d775c769..6a83073612968cdbd45ad42e97e696824aec9e53 100644
--- a/third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositor.h
+++ b/third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositor.h
@@ -17,6 +17,7 @@ class Layer;
 
 namespace gfx {
 class Transform;
+class Vector2dF;
 }
 
 namespace blink {
@@ -53,7 +54,11 @@ private:
     class ContentLayerClientImpl;
 
     // Builds a leaf layer that represents a single paint chunk.
-    scoped_refptr<cc::Layer> layerForPaintChunk(const PaintArtifact&, const PaintChunk&, gfx::Transform);
+    // Note: cc::Layer API assumes the layer bounds to start at (0, 0) but the bounding box of
+    // a paint chunk does not necessarily start at (0, 0) and could even be negative. Internally
+    // the generated layer translates the paint chunk to align the bounding box to (0, 0) and
+    // return the actual origin of the paint chunk in output parameter layerOffset.
+    scoped_refptr<cc::Layer> layerForPaintChunk(const PaintArtifact&, const PaintChunk&, gfx::Vector2dF& layerOffset);
 
     scoped_refptr<cc::Layer> m_rootLayer;
     OwnPtr<WebLayer> m_webLayer;