Introduce bottom controls to CC and let it respond to scrolling

content/browser/renderer_host/render_widget_host_view_android.cc

Index: content/browser/renderer_host/render_widget_host_view_android.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_android.cc b/content/browser/renderer_host/render_widget_host_view_android.cc
index 0a02371dbabe3a326bde2fe762bc2e9c24647ab0..86d3abe397c6eb98b032531a1a5a67c707415368 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.cc
+++ b/content/browser/renderer_host/render_widget_host_view_android.cc
@@ -635,6 +635,14 @@ float RenderWidgetHostViewAndroid::GetTopControlsHeight() const {
   return content_view_core_->GetTopControlsHeightDip();
 }
 
+float RenderWidgetHostViewAndroid::GetBottomControlsHeight() const {
+  if (!content_view_core_)
+    return 0.f;
+
+  // The height of the top controls.
+  return content_view_core_->GetBottomControlsHeightDip();
+}
+
 void RenderWidgetHostViewAndroid::UpdateCursor(const WebCursor& cursor) {
   // There are no cursors on Android.
 }
@@ -1304,6 +1312,8 @@ void RenderWidgetHostViewAndroid::OnFrameMetadataUpdated(
       frame_metadata.scrollable_viewport_size,
       frame_metadata.location_bar_offset,
       frame_metadata.location_bar_content_translation,
+      frame_metadata.bottom_bar_offset,
+      frame_metadata.bottom_bar_content_translation,
       is_mobile_optimized,
       frame_metadata.selection.start);
 #if defined(VIDEO_HOLE)