Introduce bottom controls to CC and let it respond to scrolling

cc/ipc/compositor_frame_metadata_struct_traits.h

 // 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.
 
 #ifndef CC_IPC_COMPOSITOR_FRAME_METADATA_STRUCT_TRAITS_H_
 #define CC_IPC_COMPOSITOR_FRAME_METADATA_STRUCT_TRAITS_H_
 
 #include "cc/ipc/compositor_frame_metadata.mojom.h"
 #include "cc/output/compositor_frame_metadata.h"
 
@@ skipping 39 matching lines @@
   static bool root_overflow_x_hidden(
       const cc::CompositorFrameMetadata& metadata) {
     return metadata.root_overflow_x_hidden;
   }
 
   static bool root_overflow_y_hidden(
       const cc::CompositorFrameMetadata& metadata) {
     return metadata.root_overflow_y_hidden;
   }
 
-  static gfx::Vector2dF location_bar_offset(
+  static gfx::Vector2dF top_bar_translate(
       const cc::CompositorFrameMetadata& metadata) {
-    return metadata.location_bar_offset;
+    return metadata.top_bar_translate;
   }
 
-  static gfx::Vector2dF location_bar_content_translation(
+  static gfx::Vector2dF top_bar_shown(
       const cc::CompositorFrameMetadata& metadata) {
-    return metadata.location_bar_content_translation;
+    return metadata.top_bar_shown;
+  }
+
+  static gfx::Vector2dF bottom_bar_translate(
+      const cc::CompositorFrameMetadata& metadata) {
+    return metadata.bottom_bar_translate;
+  }
+
+  static gfx::Vector2dF bottom_bar_shown(
+      const cc::CompositorFrameMetadata& metadata) {
+    return metadata.bottom_bar_shown;
   }
 
   static uint32_t root_background_color(
       const cc::CompositorFrameMetadata& metadata) {
     return metadata.root_background_color;
   }
 
   static const cc::Selection<gfx::SelectionBound>& selection(
       const cc::CompositorFrameMetadata& metadata) {
     return metadata.selection;
@@ skipping 23 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.ReadTopBarTranslate(&out->top_bar_translate) ||
+        !data.ReadTopBarShown(&out->top_bar_shown)) {
       return false;
     }
 
     out->root_background_color = data.root_background_color();
     if (!data.ReadSelection(&out->selection) ||
         !data.ReadLatencyInfo(&out->latency_info) ||
         !data.ReadSatisfiesSequences(&out->satisfies_sequences) ||
         !data.ReadReferencedSurfaces(&out->referenced_surfaces)) {
       return false;
     }
     return true;
   }
 };
 
 }  // namespace mojo
 
 #endif  // CC_IPC_COMPOSITOR_FRAME_METADATA_STRUCT_TRAITS_H_