Introduce bottom controls to CC and let it respond to scrolling

ui/android/delegated_frame_host_android.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 "ui/android/delegated_frame_host_android.h"
 
 #include "base/logging.h"
 #include "cc/layers/solid_color_layer.h"
 #include "cc/layers/surface_layer.h"
 #include "cc/output/compositor_frame.h"
@@ skipping 95 matching lines @@
   if (!surface_factory_) {
     surface_factory_ =
         base::WrapUnique(new cc::SurfaceFactory(surface_manager_, this));
   }
 
   cc::RenderPass* root_pass =
       frame.delegated_frame_data->render_pass_list.back().get();
   gfx::Size surface_size = root_pass->output_rect.size();
 
   if (!current_frame_ || surface_size != current_frame_->surface_size ||
-      current_frame_->location_bar_content_translation !=
-          frame.metadata.location_bar_content_translation ||
+      current_frame_->top_controls_height !=
+          frame.metadata.top_controls_height ||
+      current_frame_->top_controls_shown_ratio !=
+          frame.metadata.top_controls_shown_ratio ||
+      current_frame_->bottom_controls_height !=
+          frame.metadata.bottom_controls_height ||
+      current_frame_->bottom_controls_shown_ratio !=
+          frame.metadata.bottom_controls_shown_ratio ||
       current_frame_->viewport_selection != frame.metadata.selection) {
     DestroyDelegatedContent();
     DCHECK(!content_layer_);
     DCHECK(!current_frame_);
 
     current_frame_ = base::MakeUnique<FrameData>();
     current_frame_->surface_id = surface_id_allocator_->GenerateId();
     surface_factory_->Create(current_frame_->surface_id);
 
     current_frame_->surface_size = surface_size;
-    current_frame_->location_bar_content_translation =
-        frame.metadata.location_bar_content_translation;
+    current_frame_->top_controls_height = frame.metadata.top_controls_height;
+    current_frame_->top_controls_shown_ratio =
+        frame.metadata.top_controls_shown_ratio;
+    current_frame_->bottom_controls_height =
+        frame.metadata.bottom_controls_height;
+    current_frame_->bottom_controls_shown_ratio =
+        frame.metadata.bottom_controls_shown_ratio;
+
     current_frame_->viewport_selection = frame.metadata.selection;
     content_layer_ =
         CreateSurfaceLayer(surface_manager_, current_frame_->surface_id,
                            current_frame_->surface_size);
     view_->GetLayer()->AddChild(content_layer_);
     UpdateBackgroundLayer();
   }
 
   surface_factory_->SubmitCompositorFrame(current_frame_->surface_id,
                                           std::move(frame), draw_callback);
@@ skipping 82 matching lines @@
   // The background layer draws in 2 cases:
   // 1) When we don't have any content from the renderer.
   // 2) When the bounds of the content received from the renderer does not match
   // the desired content bounds.
   bool background_is_drawable = false;
 
   if (current_frame_) {
     float device_scale_factor = gfx::DeviceDisplayInfo().GetDIPScale();
     gfx::Size content_size_in_dip = gfx::ConvertSizeToDIP(
         device_scale_factor, current_frame_->surface_size);
+    float top_bar_shown = current_frame_->top_controls_height *
+                          current_frame_->top_controls_shown_ratio;
+    float bottom_bar_shown = current_frame_->bottom_controls_height *
+                             current_frame_->bottom_controls_shown_ratio;
     content_size_in_dip.set_height(
-        content_size_in_dip.height() +
-        current_frame_->location_bar_content_translation.y());
+        content_size_in_dip.height() - top_bar_shown - bottom_bar_shown);
     background_is_drawable =
         content_size_in_dip.width() < container_size_in_dip_.width() ||
         content_size_in_dip.height() < container_size_in_dip_.height();
   } else {
     background_is_drawable = true;
   }
 
   background_layer_->SetIsDrawable(background_is_drawable);
 }
 
 }  // namespace ui