Add reference-counting for mailbox textures.

gpu/command_buffer/service/mailbox_manager.h

Index: gpu/command_buffer/service/mailbox_manager.h
diff --git a/gpu/command_buffer/service/mailbox_manager.h b/gpu/command_buffer/service/mailbox_manager.h
index 8f97dd4af6d867b4ee96b906c8af998b186649da..b08f5c1dce261559ba3595d79cfc7bed026dfedf 100644
--- a/gpu/command_buffer/service/mailbox_manager.h
+++ b/gpu/command_buffer/service/mailbox_manager.h
@@ -25,7 +25,6 @@ namespace gpu {
 namespace gles2 {
 
 class TextureDefinition;
-class TextureManager;
 
 // Identifies a mailbox where a texture definition can be stored for
 // transferring textures between contexts that are not in the same context
@@ -50,12 +49,10 @@ class GPU_EXPORT MailboxManager : public base::RefCounted<MailboxManager> {
   // Put the texture definition in the named mailbox.
   bool ProduceTexture(unsigned target,
                       const MailboxName& name,
-                      TextureDefinition* definition,
-                      TextureManager* owner);
+                      TextureDefinition* definition);
 
-  // Destroy any texture definitions and mailboxes owned by the given texture
-  // manager.
-  void DestroyOwnedTextures(TextureManager* owner, bool have_context);
+  // Removes a texture definition from the mailbox.
+  void OnDestroyTexture(TextureDefinition* definition);
 
   std::string private_key() {
     return std::string(private_key_, sizeof(private_key_));
@@ -77,17 +74,9 @@ class GPU_EXPORT MailboxManager : public base::RefCounted<MailboxManager> {
 
   static bool TargetNameLess(const TargetName& lhs, const TargetName& rhs);
 
-  struct OwnedTextureDefinition {
-    OwnedTextureDefinition(TextureDefinition* definition,
-                           TextureManager* owner);
-    ~OwnedTextureDefinition();
-    linked_ptr<TextureDefinition> definition;
-    TextureManager* owner;
-  };
-
   typedef std::map<
       TargetName,
-      OwnedTextureDefinition,
+      TextureDefinition*,
       std::pointer_to_binary_function<
           const TargetName&, const TargetName&, bool> > TextureDefinitionMap;