Introduce bottom controls to CC and let it respond to scrolling

content/renderer/gpu/render_widget_compositor.cc

 // Copyright (c) 2013 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 "content/renderer/gpu/render_widget_compositor.h"
 
 #include <stddef.h>
 #include <limits>
 #include <string>
 #include <utility>
@@ skipping 992 matching lines @@
 }
 
 void RenderWidgetCompositor::setTopControlsHeight(float height, bool shrink) {
   layer_tree_host_->GetLayerTree()->SetTopControlsHeight(height, shrink);
 }
 
 void RenderWidgetCompositor::setTopControlsShownRatio(float ratio) {
   layer_tree_host_->GetLayerTree()->SetTopControlsShownRatio(ratio);
 }
 
+void RenderWidgetCompositor::setBottomControlsHeight(float height) {
+  layer_tree_host_->GetLayerTree()->SetBottomControlsHeight(height);
+}
+
 void RenderWidgetCompositor::WillBeginMainFrame() {
   delegate_->WillBeginCompositorFrame();
 }
 
 void RenderWidgetCompositor::DidBeginMainFrame() {
 }
 
 void RenderWidgetCompositor::BeginMainFrame(const cc::BeginFrameArgs& args) {
   compositor_deps_->GetRendererScheduler()->WillBeginFrame(args);
   double frame_time_sec = (args.frame_time - base::TimeTicks()).InSecondsF();
@@ skipping 123 matching lines @@
 
   remote_proto_channel_receiver_->OnProtoReceived(std::move(deserialized));
 }
 
 void RenderWidgetCompositor::SetPaintedDeviceScaleFactor(
     float device_scale) {
   layer_tree_host_->GetLayerTree()->SetPaintedDeviceScaleFactor(device_scale);
 }
 
 }  // namespace content