Plumb an overscroll callback form the compositor to the Android UI thread.

content/renderer/render_view_impl_android.cc

Index: content/renderer/render_view_impl_android.cc
diff --git a/content/renderer/render_view_impl_android.cc b/content/renderer/render_view_impl_android.cc
index 18a42b5ff872fef03484253b8d576bf1e76f6af7..0ca688c13aecf61140ff028c64916888e0bd92d1 100644
--- a/content/renderer/render_view_impl_android.cc
+++ b/content/renderer/render_view_impl_android.cc
@@ -35,13 +35,15 @@ void RenderViewImpl::SendUpdateFrameInfo() {
   if (!webview() || !webview()->mainFrame())
     return;
 
-  Send(new ViewHostMsg_UpdateFrameInfo(
-      routing_id_,
-      GetScrollOffset(),
-      webview()->pageScaleFactor(),
-      webview()->minimumPageScaleFactor(),
-      webview()->maximumPageScaleFactor(),
-      gfx::Size(webview()->mainFrame()->contentsSize())));
+  ViewHostMsg_UpdateFrameInfo_Params params;
+  params.scroll_offset = GetScrollOffset();
+  params.unused_scroll_delta = gfx::Vector2d();
+  params.page_scale_factor = webview()->pageScaleFactor();
+  params.min_page_scale_factor = webview()->minimumPageScaleFactor();
+  params.max_page_scale_factor = webview()->maximumPageScaleFactor();
+  params.content_size = gfx::Size(webview()->mainFrame()->contentsSize());
+
+  Send(new ViewHostMsg_UpdateFrameInfo(routing_id_, params));
 }
 
 }  // namespace content