Add a base class of Texture for interfacing with the mailbox manager.

gpu/command_buffer/service/mailbox_manager_sync.h

Index: gpu/command_buffer/service/mailbox_manager_sync.h
diff --git a/gpu/command_buffer/service/mailbox_manager_sync.h b/gpu/command_buffer/service/mailbox_manager_sync.h
index 1e232b3966d3e90ea386dbcd7aa881b087816c19..f110cf1145c869a6d3dae04b127d378f552ba85c 100644
--- a/gpu/command_buffer/service/mailbox_manager_sync.h
+++ b/gpu/command_buffer/service/mailbox_manager_sync.h
@@ -20,7 +20,7 @@
 namespace gpu {
 namespace gles2 {
 
-class Texture;
+class TextureBase;
 class TextureManager;
 
 // Manages resources scoped beyond the context or context group level
@@ -31,12 +31,12 @@ class GPU_EXPORT MailboxManagerSync : public MailboxManager {
   MailboxManagerSync();
 
   // MailboxManager implementation:
-  Texture* ConsumeTexture(const Mailbox& mailbox) override;
-  void ProduceTexture(const Mailbox& mailbox, Texture* texture) override;
+  TextureBase* ConsumeTexture(const Mailbox& mailbox) override;
+  void ProduceTexture(const Mailbox& mailbox, TextureBase* texture) override;
   bool UsesSync() override;
   void PushTextureUpdates(const SyncToken& token) override;
   void PullTextureUpdates(const SyncToken& token) override;
-  void TextureDeleted(Texture* texture) override;
+  void TextureDeleted(TextureBase* texture) override;
 
  private:
   friend class base::RefCounted<MailboxManager>;
@@ -84,7 +84,7 @@ class GPU_EXPORT MailboxManagerSync : public MailboxManager {
     unsigned version;
     scoped_refptr<TextureGroup> group;
   };
-  static void UpdateDefinitionLocked(Texture* texture,
+  static void UpdateDefinitionLocked(TextureBase* texture,
                                      TextureGroupRef* group_ref);
 
   typedef std::map<Texture*, TextureGroupRef> TextureToGroupMap;