Mark layers that can use LCD text based on layer transform and opacity.

cc/content_layer.h

 // Copyright 2010 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_CONTENT_LAYER_H_
 #define CC_CONTENT_LAYER_H_
 
 #include "base/basictypes.h"
 #include "cc/cc_export.h"
 #include "cc/layer_painter.h"
@@ skipping 19 matching lines @@
 
     DISALLOW_COPY_AND_ASSIGN(ContentLayerPainter);
 };
 
 // A layer that renders its contents into an SkCanvas.
 class CC_EXPORT ContentLayer : public TiledLayer {
 public:
     static scoped_refptr<ContentLayer> create(ContentLayerClient*);
 
     void clearClient() { m_client = 0; }
+    bool useLCDText() const { return m_useLCDText; }
 
     virtual bool drawsContent() const OVERRIDE;
     virtual void setTexturePriorities(const PriorityCalculator&) OVERRIDE;
     virtual void update(ResourceUpdateQueue&, const OcclusionTracker*, RenderingStats&) OVERRIDE;
     virtual bool needMoreUpdates() OVERRIDE;
 
     virtual void setContentsOpaque(bool) OVERRIDE;
 
 protected:
     explicit ContentLayer(ContentLayerClient*);
     virtual ~ContentLayer();
 
 private:
     virtual LayerUpdater* updater() const OVERRIDE;
     virtual void createUpdaterIfNeeded() OVERRIDE;
 
+    void updateUseLCDText();
+    // Called when LCD text setting is about to potentially change.
+    // If this function returns true, the setting is allowed to change.
+    // If it returns false, the setting is not changed.
+    bool useLCDTextWillChange() const;
+    void useLCDTextDidChange();
+
     ContentLayerClient* m_client;
     scoped_refptr<LayerUpdater> m_updater;
+
+    bool m_useLCDText;
+    int m_lcdTextChangeCount;
+    static const int kLCDTextMaxChangeCount;
 };
 
 }
 #endif  // CC_CONTENT_LAYER_H_