Uber Comp: never change mailbox name associated with a texture object.

cc/resource_provider.h

Index: cc/resource_provider.h
===================================================================
--- cc/resource_provider.h	(revision 166046)
+++ cc/resource_provider.h	(working copy)
@@ -131,9 +131,6 @@
     // will wait on it.
     void receiveFromParent(const TransferableResourceList&);
 
-    // Only for testing
-    size_t mailboxCount() const { return m_mailboxes.size(); }
-
     // The following lock classes are part of the ResourceProvider API and are
     // needed to read and write the resource contents. The user must ensure
     // that they only use GL locks on GL resources, etc, and this is enforced
@@ -207,10 +204,12 @@
 private:
     struct Resource {
         Resource();
-        Resource(unsigned textureId, int pool, const gfx::Size& size, GLenum format);
+        Resource(unsigned textureId, const Mailbox& mailbox, int pool,
+                 const gfx::Size& size, GLenum format);
         Resource(uint8_t* pixels, int pool, const gfx::Size& size, GLenum format);
 
         unsigned glId;
+        Mailbox mailbox;
         uint8_t* pixels;
         int pool;
         int lockForReadCount;
@@ -243,7 +242,6 @@
     static void populateSkBitmapWithResource(SkBitmap*, const Resource*);
 
     bool transferResource(WebKit::WebGraphicsContext3D*, ResourceId, TransferableResource*);
-    void trimMailboxDeque();
     void deleteResourceInternal(ResourceMap::iterator it);
 
     GraphicsContext* m_context;
@@ -252,8 +250,6 @@
     int m_nextChild;
     ChildMap m_children;
 
-    std::deque<Mailbox> m_mailboxes;
-
     ResourceType m_defaultResourceType;
     bool m_useTextureStorageExt;
     bool m_useTextureUsageHint;