Delegate root layer scroll offset to android_webview.

content/renderer/android/synchronous_compositor_impl.h

Index: content/renderer/android/synchronous_compositor_impl.h
diff --git a/content/renderer/android/synchronous_compositor_impl.h b/content/renderer/android/synchronous_compositor_impl.h
index 35317b7ee3b4932dad689ef38e42b4e9be04d4ab..8845d8155c45130f153b085affbbd9039204d54d 100644
--- a/content/renderer/android/synchronous_compositor_impl.h
+++ b/content/renderer/android/synchronous_compositor_impl.h
@@ -25,7 +25,8 @@ namespace content {
 // from the Compositor thread.
 class SynchronousCompositorImpl
     : public SynchronousCompositor,
-      public SynchronousCompositorOutputSurfaceDelegate {
+      public SynchronousCompositorOutputSurfaceDelegate,
+      public cc::LayerScrollOffsetDelegate {
  public:
   explicit SynchronousCompositorImpl(int32 routing_id);
   virtual ~SynchronousCompositorImpl();
@@ -47,6 +48,10 @@ class SynchronousCompositorImpl
   virtual void DidCreateSynchronousOutputSurface() OVERRIDE;
   virtual void DidDestroySynchronousOutputSurface() OVERRIDE;
 
+  // LayerScrollOffsetDelegate
+  virtual void SetTotalScrollOffset(gfx::Vector2dF new_value) OVERRIDE;
+  virtual gfx::Vector2dF GetTotalScrollOffset() OVERRIDE;
+
  private:
   bool CalledOnValidThread() const;