ui: Add debug flag to show composited layer borders in ChromeOS UI.

cc/debug/layer_tree_debug_state.h

 // Copyright 2011 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.
 
 #ifndef CC_DEBUG_LAYER_TREE_DEBUG_STATE_H_
 #define CC_DEBUG_LAYER_TREE_DEBUG_STATE_H_
 
+#include <bitset>
+
 #include "cc/debug/debug_export.h"
 
 namespace cc {
 
 namespace proto {
 class LayerTreeDebugState;
 }  // namespace proto
 
+enum DebugBorderType {
+  RENDERPASS = 0,
+  SURFACE,
+  LAYER,
+  LAST_DEBUG_BORDER_TYPE = LAYER
+};
+using DebugBorderTypes = std::bitset<LAST_DEBUG_BORDER_TYPE + 1>;
+
 class CC_DEBUG_EXPORT LayerTreeDebugState {
  public:
   LayerTreeDebugState();
   LayerTreeDebugState(const LayerTreeDebugState& other);
   ~LayerTreeDebugState();
 
   bool show_fps_counter;
-  bool show_debug_borders;
+  DebugBorderTypes show_debug_borders;
 
   bool show_paint_rects;
   bool show_property_changed_rects;
   bool show_surface_damage_rects;
   bool show_screen_space_rects;
   bool show_touch_event_handler_rects;
   bool show_wheel_event_handler_rects;
   bool show_scroll_event_handler_rects;
   bool show_non_fast_scrollable_rects;
   bool show_layer_animation_bounds_rects;
@@ skipping 13 matching lines @@
   static LayerTreeDebugState Unite(const LayerTreeDebugState& a,
                                    const LayerTreeDebugState& b);
 
  private:
   bool record_rendering_stats_;
 };
 
 }  // namespace cc
 
 #endif  // CC_DEBUG_LAYER_TREE_DEBUG_STATE_H_