LayerTreeHost should not modify the LayerTreeSettings object. Instead it should use a temporary va…

cc/trees/layer_tree_host.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_TREES_LAYER_TREE_HOST_H_
 #define CC_TREES_LAYER_TREE_HOST_H_
 
 #include <limits>
 #include <list>
 #include <vector>
@@ skipping 342 matching lines @@
 
   scoped_refptr<Layer> root_layer_;
   scoped_refptr<HeadsUpDisplayLayer> hud_layer_;
 
   scoped_ptr<PrioritizedResourceManager> contents_texture_manager_;
   scoped_ptr<PrioritizedResource> surface_memory_placeholder_;
 
   base::WeakPtr<InputHandler> input_handler_weak_ptr_;
   base::WeakPtr<TopControlsManager> top_controls_manager_weak_ptr_;
 
-  LayerTreeSettings settings_;
+  const LayerTreeSettings settings_;
   LayerTreeDebugState debug_state_;
 
   gfx::Size device_viewport_size_;
   float overdraw_bottom_height_;
   float device_scale_factor_;
 
   bool visible_;
 
   typedef base::hash_map<WebKit::WebGraphicsContext3D*,
                          scoped_refptr<RateLimiter> > RateLimiterMap;
@@ skipping 44 matching lines @@
   };
   LCDTextMetrics lcd_text_metrics_;
   int tree_id_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHost);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_H_