Remove static thread pointers from CC

cc/prioritized_texture.h

Index: cc/prioritized_texture.h
diff --git a/cc/prioritized_texture.h b/cc/prioritized_texture.h
index 1939f9f0beb8a1c9aabb99094f49332dd1539b9e..55a57f0f6b066628200092c16f7d795b3ba82ace 100644
--- a/cc/prioritized_texture.h
+++ b/cc/prioritized_texture.h
@@ -18,6 +18,7 @@
 namespace cc {
 
 class PrioritizedTextureManager;
+class Proxy;
 
 class PrioritizedTexture {
 public:
@@ -104,6 +105,8 @@ private:
         bool resourceHasBeenDeleted() const;
 
     private:
+        const Proxy* proxy() const;
+
         friend class PrioritizedTexture;
         PrioritizedTexture* m_owner;
         int m_priorityAtLastPriorityUpdate;
@@ -116,7 +119,6 @@ private:
 #ifndef NDEBUG
         ResourceProvider* m_resourceProvider;
 #endif
-
         DISALLOW_COPY_AND_ASSIGN(Backing);
     };