Introduce bottom controls to CC and let it respond to scrolling

cc/ipc/compositor_frame_metadata_struct_traits.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/ipc/compositor_frame_metadata_struct_traits.h"
 #include "cc/ipc/selection_struct_traits.h"
 #include "cc/ipc/surface_id_struct_traits.h"
 #include "ui/events/mojo/latency_info_struct_traits.h"
 #include "ui/gfx/mojo/selection_bound_struct_traits.h"
 
@@ skipping 11 matching lines @@
   out->page_scale_factor = data.page_scale_factor();
   if (!data.ReadScrollableViewportSize(&out->scrollable_viewport_size) ||
       !data.ReadRootLayerSize(&out->root_layer_size)) {
     return false;
   }
 
   out->min_page_scale_factor = data.min_page_scale_factor();
   out->max_page_scale_factor = data.max_page_scale_factor();
   out->root_overflow_x_hidden = data.root_overflow_x_hidden();
   out->root_overflow_y_hidden = data.root_overflow_y_hidden();
-  if (!data.ReadLocationBarOffset(&out->location_bar_offset) ||
-      !data.ReadLocationBarContentTranslation(
-          &out->location_bar_content_translation)) {
+  if (!data.ReadTopControlsHeight(&out->top_controls_height)) {
     return false;
   }
+  out->top_controls_shown_ratio = data.top_controls_shown_ratio();
+  if (!data.ReadBottomControlsHeight(&out->bottom_controls_height)) {
+    return false;
+  }
+  out->bottom_controls_shown_ratio = data.bottom_controls_shown_ratio();
 
   out->root_background_color = data.root_background_color();
   return data.ReadSelection(&out->selection) &&
          data.ReadLatencyInfo(&out->latency_info) &&
          data.ReadSatisfiesSequences(&out->satisfies_sequences) &&
          data.ReadReferencedSurfaces(&out->referenced_surfaces);
 }
 
 }  // namespace mojo