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 f0ab136cc2c07b90c420eae0fc47ca8eac2f8e2e..883cb7600e0c3950d03b31993bda2e43b062946c 100644
--- a/cc/prioritized_texture.h
+++ b/cc/prioritized_texture.h
@@ -18,6 +18,7 @@
 namespace cc {
 
 class PrioritizedTextureManager;
+class Proxy;
 
 class PrioritizedTexture {
 public:
@@ -106,6 +107,8 @@ private:
         bool resourceHasBeenDeleted() const;
 
     private:
+        const Proxy* proxy() const;
+
         friend class PrioritizedTexture;
         PrioritizedTexture* m_owner;
         int m_priorityAtLastPriorityUpdate;
@@ -118,7 +121,6 @@ private:
 #ifndef NDEBUG
         ResourceProvider* m_resourceProvider;
 #endif
-
         DISALLOW_COPY_AND_ASSIGN(Backing);
     };