Use WebKit compositor in ui::Layer

ui/gfx/compositor/layer.h

Index: ui/gfx/compositor/layer.h
diff --git a/ui/gfx/compositor/layer.h b/ui/gfx/compositor/layer.h
index 06b3d02b1f45fa591c8d09573f82824c037b33dd..91dc05f0650210ca5341d27c73beb68f882c4a55 100644
--- a/ui/gfx/compositor/layer.h
+++ b/ui/gfx/compositor/layer.h
@@ -12,6 +12,9 @@
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebContentLayer.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebContentLayerClient.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebLayerClient.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/transform.h"
 #include "ui/gfx/compositor/compositor.h"
@@ -35,7 +38,10 @@ class Texture;
 // NOTE: unlike Views, each Layer does *not* own its children views. If you
 // delete a Layer and it has children, the parent of each child layer is set to
 // NULL, but the children are not deleted.
-class COMPOSITOR_EXPORT Layer : public LayerAnimatorDelegate {
+class COMPOSITOR_EXPORT Layer :
+    public LayerAnimatorDelegate,
+    NON_EXPORTED_BASE(public WebKit::WebLayerClient),
+    NON_EXPORTED_BASE(public WebKit::WebContentLayerClient) {
  public:
   enum LayerType {
     LAYER_HAS_NO_TEXTURE = 0,
@@ -118,7 +124,7 @@ class COMPOSITOR_EXPORT Layer : public LayerAnimatorDelegate {
 
   // Returns true if this layer can have a texture (has_texture_ is true)
   // and is not completely obscured by a child.
-  bool ShouldDraw();
+  bool ShouldDraw() const;
 
   // Converts a point from the coordinates of |source| to the coordinates of
   // |target|. Necessarily, |source| and |target| must inhabit the same Layer
@@ -166,6 +172,16 @@ class COMPOSITOR_EXPORT Layer : public LayerAnimatorDelegate {
   // (e.g. the GPU process on TOUCH_UI).
   bool layer_updated_externally() const { return layer_updated_externally_; }
 
+  // WebLayerClient
+  virtual void notifyNeedsComposite();
+
+  // WebContentLayerClient
+  virtual void paintContents(WebKit::WebCanvas*, const WebKit::WebRect& clip);
+
+#if defined(USE_WEBKIT_COMPOSITOR)
+  WebKit::WebContentLayer web_layer() { return web_layer_; }
+#endif
+
  private:
   // TODO(vollick): Eventually, if a non-leaf node has an opacity of less than
   // 1.0, we'll render to a separate texture, and then apply the alpha.
@@ -240,6 +256,12 @@ class COMPOSITOR_EXPORT Layer : public LayerAnimatorDelegate {
   virtual void SetTransformFromAnimator(const Transform& transform) OVERRIDE;
   virtual void SetOpacityFromAnimator(float opacity) OVERRIDE;
 
+#if defined(USE_WEBKIT_COMPOSITOR)
+  void CreateWebLayer();
+  void RecomputeTransform();
+  void RecomputeDrawsContent();
+#endif
+
   const LayerType type_;
 
   Compositor* compositor_;
@@ -272,6 +294,10 @@ class COMPOSITOR_EXPORT Layer : public LayerAnimatorDelegate {
 
   scoped_ptr<LayerAnimator> animator_;
 
+#if defined(USE_WEBKIT_COMPOSITOR)
+  WebKit::WebContentLayer web_layer_;
+#endif
+
   DISALLOW_COPY_AND_ASSIGN(Layer);
 };