Aura-Mus: Implement gutter in the embedder.

ui/compositor/layer.cc

 // Copyright (c) 2012 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/compositor/layer.h"
 
 #include <algorithm>
 #include <memory>
 #include <utility>
 
@@ skipping 668 matching lines @@
   DCHECK(type_ == LAYER_TEXTURED || type_ == LAYER_SOLID_COLOR);
   DCHECK(surface_layer_);
 
   // TODO(fsamuel): We should compute the gutter in the display compositor.
   surface_layer_->SetFallbackSurfaceInfo(surface_info);
 
   for (const auto& mirror : mirrors_)
     mirror->dest()->SetFallbackSurface(surface_info);
 }
 
+const cc::SurfaceInfo* Layer::GetFallbackSurfaceInfo() const {
+  if (surface_layer_)
+    return &surface_layer_->fallback_surface_info();
+  return nullptr;
+}
+
 void Layer::SetShowSolidColorContent() {
   DCHECK_EQ(type_, LAYER_SOLID_COLOR);
 
   if (solid_color_layer_.get())
     return;
 
   scoped_refptr<cc::SolidColorLayer> new_layer = cc::SolidColorLayer::Create();
   SwitchToLayer(new_layer);
   solid_color_layer_ = new_layer;
 
@@ skipping 488 matching lines @@
   const auto it = std::find_if(mirrors_.begin(), mirrors_.end(),
       [mirror](const std::unique_ptr<LayerMirror>& mirror_ptr) {
         return mirror_ptr.get() == mirror;
       });
 
   DCHECK(it != mirrors_.end());
   mirrors_.erase(it);
 }
 
 }  // namespace ui