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 46129fb5a079b2235d222acac76b54d3aa5a26c3..6846f0373a675a9e94ade03f8bc45522af60220b 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.cc
+++ b/content/browser/renderer_host/render_widget_host_view_android.cc
@@ -633,6 +633,14 @@ 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.
 }
@@ -1000,8 +1008,8 @@ void RenderWidgetHostViewAndroid::SubmitCompositorFrame(
   }
   if (surface_id_.is_null() ||
       texture_size_in_layer_ != current_surface_size_ ||
-      location_bar_content_translation_ !=
-          frame.metadata.location_bar_content_translation ||
+      top_bar_shown_ratio_ != frame.metadata.top_controls_shown_ratio ||
+      bottom_bar_shown_ratio_ != frame.metadata.bottom_controls_shown_ratio ||
       current_viewport_selection_ != frame.metadata.selection) {
     RemoveLayers();
     if (!surface_id_.is_null())
@@ -1013,8 +1021,8 @@ void RenderWidgetHostViewAndroid::SubmitCompositorFrame(
     DCHECK(layer_);
 
     current_surface_size_ = texture_size_in_layer_;
-    location_bar_content_translation_ =
-        frame.metadata.location_bar_content_translation;
+    top_bar_shown_ratio_ = frame.metadata.top_controls_shown_ratio;
+    bottom_bar_shown_ratio_ = frame.metadata.bottom_controls_shown_ratio;
     current_viewport_selection_ = frame.metadata.selection;
     AttachLayers();
   }
@@ -1253,10 +1261,9 @@ void RenderWidgetHostViewAndroid::OnFrameMetadataUpdated(
     // Set parameters for adaptive handle orientation.
     gfx::SizeF viewport_size(frame_metadata.scrollable_viewport_size);
     viewport_size.Scale(frame_metadata.page_scale_factor);
-    gfx::RectF viewport_rect(
-        frame_metadata.location_bar_content_translation.x(),
-        frame_metadata.location_bar_content_translation.y(),
-        viewport_size.width(), viewport_size.height());
+    gfx::RectF viewport_rect(0.0f, frame_metadata.top_controls_height.y() *
+                                       frame_metadata.top_controls_shown_ratio,
+                             viewport_size.width(), viewport_size.height());
     selection_controller_->OnViewportChanged(viewport_rect);
   }
 
@@ -1270,8 +1277,10 @@ void RenderWidgetHostViewAndroid::OnFrameMetadataUpdated(
                      frame_metadata.max_page_scale_factor),
       frame_metadata.root_layer_size,
       frame_metadata.scrollable_viewport_size,
-      frame_metadata.location_bar_offset,
-      frame_metadata.location_bar_content_translation,
+      frame_metadata.top_controls_height,
+      frame_metadata.top_controls_shown_ratio,
+      frame_metadata.bottom_controls_height,
+      frame_metadata.bottom_controls_shown_ratio,
       is_mobile_optimized,
       frame_metadata.selection.start);
 #if defined(VIDEO_HOLE)