Use bit fields inside cc to reduce memory usage.

cc/layers/layer_impl.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_LAYERS_LAYER_IMPL_H_
 #define CC_LAYERS_LAYER_IMPL_H_
 
 #include <set>
 #include <string>
 
@@ skipping 34 matching lines @@
 
 namespace cc {
 
 class LayerTreeHostImpl;
 class LayerTreeImpl;
 class MicroBenchmarkImpl;
 class QuadSink;
 class Renderer;
 class ScrollbarAnimationController;
 class ScrollbarLayerImplBase;
-class Layer;
 
 struct AppendQuadsData;
 
 enum DrawMode {
   DRAW_MODE_NONE,
   DRAW_MODE_HARDWARE,
   DRAW_MODE_SOFTWARE,
   DRAW_MODE_RESOURCELESS_SOFTWARE
 };
 
@@ skipping 503 matching lines @@
   scoped_ptr<LayerImpl> replica_layer_;
   int layer_id_;
   LayerTreeImpl* layer_tree_impl_;
 
   // Properties synchronized from the associated Layer.
   gfx::PointF anchor_point_;
   float anchor_point_z_;
   gfx::Size bounds_;
   gfx::Vector2d scroll_offset_;
   LayerScrollOffsetDelegate* scroll_offset_delegate_;
-  bool scrollable_;
-  bool should_scroll_on_main_thread_;
-  bool have_wheel_event_handlers_;
-  bool user_scrollable_horizontal_;
-  bool user_scrollable_vertical_;
+  bool scrollable_ : 1;
+  bool should_scroll_on_main_thread_ : 1;
+  bool have_wheel_event_handlers_ : 1;
+  bool user_scrollable_horizontal_ : 1;
+  bool user_scrollable_vertical_ : 1;
+  bool stacking_order_changed_ : 1;
+  // Whether the "back" of this layer should draw.
+  bool double_sided_ : 1;
+
+  // Tracks if drawing-related properties have changed since last redraw.
+  bool layer_property_changed_ : 1;
+
+  bool masks_to_bounds_ : 1;
+  bool contents_opaque_ : 1;
+  bool is_root_for_isolated_group_ : 1;
+  bool preserves_3d_ : 1;
+  bool use_parent_backface_visibility_ : 1;
+  bool draw_checkerboard_for_missing_tiles_ : 1;
+  bool draws_content_ : 1;
+  bool hide_layer_and_subtree_ : 1;
+  bool force_render_surface_ : 1;
+
+  // Set for the layer that other layers are fixed to.
+  bool is_container_for_fixed_position_layers_ : 1;
   Region non_fast_scrollable_region_;
   Region touch_event_handler_region_;
   SkColor background_color_;
-  bool stacking_order_changed_;
 
-  // Whether the "back" of this layer should draw.
-  bool double_sided_;
-
-  // Tracks if drawing-related properties have changed since last redraw.
-  bool layer_property_changed_;
-
-  bool masks_to_bounds_;
-  bool contents_opaque_;
   float opacity_;
   SkXfermode::Mode blend_mode_;
-  bool is_root_for_isolated_group_;
   gfx::PointF position_;
-  bool preserves_3d_;
-  bool use_parent_backface_visibility_;
-  bool draw_checkerboard_for_missing_tiles_;
   gfx::Transform sublayer_transform_;
   gfx::Transform transform_;
 
-  bool draws_content_;
-  bool hide_layer_and_subtree_;
-  bool force_render_surface_;
-
-  // Set for the layer that other layers are fixed to.
-  bool is_container_for_fixed_position_layers_;
   // This property is effective when
   // is_container_for_fixed_position_layers_ == true,
   gfx::Vector2dF fixed_container_size_delta_;
 
   LayerPositionConstraint position_constraint_;
 
   gfx::Vector2dF scroll_delta_;
   gfx::Vector2d sent_scroll_delta_;
   gfx::Vector2d max_scroll_offset_;
   gfx::Vector2dF last_scroll_offset_;
@@ skipping 36 matching lines @@
   DrawProperties<LayerImpl> draw_properties_;
 
   scoped_refptr<base::debug::ConvertableToTraceFormat> debug_info_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_LAYER_IMPL_H_