Add support for calculating the position of the top controls in the cc layer.

cc/compositor_frame_metadata.h

Index: cc/compositor_frame_metadata.h
diff --git a/cc/compositor_frame_metadata.h b/cc/compositor_frame_metadata.h
index 92a48ffba2c4aaff0a7955bd41ddf99e20e44b1c..5d9a9056a1e61298a1bd2b3d088cc52ff61c4bc4 100644
--- a/cc/compositor_frame_metadata.h
+++ b/cc/compositor_frame_metadata.h
@@ -29,9 +29,10 @@ class CC_EXPORT CompositorFrameMetadata
   float min_page_scale_factor;
   float max_page_scale_factor;
 
-  // Used to position the Android location top bar, whose precise
-  // position is computed by the renderer compositor.
+  // Used to position the Android location top bar and page content, whose
+  // precise position is computed by the renderer compositor.
   gfx::Vector2dF location_bar_offset;
+  gfx::Vector2dF location_bar_content_translation;
 };
 
 }  // namespace cc