Delegate root layer scroll offset to android_webview.

android_webview/browser/in_process_view_renderer.h

Index: android_webview/browser/in_process_view_renderer.h
diff --git a/android_webview/browser/in_process_view_renderer.h b/android_webview/browser/in_process_view_renderer.h
index 4175dd1cdeeb6239a505eeb6a5b98bdc7ccbf774..ab8193aeedb3916c6ce76546660590d609f12b19 100644
--- a/android_webview/browser/in_process_view_renderer.h
+++ b/android_webview/browser/in_process_view_renderer.h
@@ -53,6 +53,8 @@ class InProcessViewRenderer : public BrowserViewRenderer,
   virtual void DidDestroyCompositor(
       content::SynchronousCompositor* compositor) OVERRIDE;
   virtual void SetContinuousInvalidate(bool invalidate) OVERRIDE;
+  virtual void SetTotalRootLayerScrollOffset(gfx::Vector2dF new_value) OVERRIDE;
+  virtual gfx::Vector2dF GetTotalRootLayerScrollOffset() OVERRIDE;
 
   void WebContentsGone();
 
@@ -91,6 +93,8 @@ class InProcessViewRenderer : public BrowserViewRenderer,
   // Last View scroll before hardware rendering is triggered.
   gfx::Point hw_rendering_scroll_;
 
+  gfx::Vector2dF scroll_offset_;
+
   base::WeakPtrFactory<InProcessViewRenderer> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(InProcessViewRenderer);