cc: Stop using magic numbers to detect if we can use partial updates.

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 254 matching lines @@
 
   void SetImplTransform(const gfx::Transform& transform);
   void SetLatencyInfo(const ui::LatencyInfo& latency_info);
 
   virtual void StartRateLimiter(WebKit::WebGraphicsContext3D* context3d);
   virtual void StopRateLimiter(WebKit::WebGraphicsContext3D* context3d);
 
   // RateLimiterClient implementation.
   virtual void RateLimit() OVERRIDE;
 
-  bool buffered_updates() const {
-    return settings_.max_partial_texture_updates !=
-        std::numeric_limits<size_t>::max();
-  }
+  bool AlwaysUsePartialTextureUpdates();
   bool RequestPartialTextureUpdate();
 
   void SetDeviceScaleFactor(float device_scale_factor);
   float device_scale_factor() const { return device_scale_factor_; }
 
   void UpdateTopControlsState(TopControlsState constraints,
                               TopControlsState current,
                               bool animate);
 
   HeadsUpDisplayLayer* hud_layer() const { return hud_layer_.get(); }
@@ skipping 162 matching lines @@
   scoped_refptr<Layer> page_scale_layer_;
   scoped_refptr<Layer> inner_viewport_scroll_layer_;
   scoped_refptr<Layer> outer_viewport_scroll_layer_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHost);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_H_