gpu: Change Produce/ConsumeTexture to allow texture sharing

gpu/command_buffer/service/texture_manager.h

Index: gpu/command_buffer/service/texture_manager.h
diff --git a/gpu/command_buffer/service/texture_manager.h b/gpu/command_buffer/service/texture_manager.h
index af5eb0ccf2209973f869c27ca023ea9965f3edba..7620b2b25b36db2295f3dc1b0c510e4700fab6c8 100644
--- a/gpu/command_buffer/service/texture_manager.h
+++ b/gpu/command_buffer/service/texture_manager.h
@@ -27,7 +27,7 @@ class Display;
 class ErrorState;
 class FeatureInfo;
 class FramebufferManager;
-class TextureDefinition;
+class MailboxManager;
 class TextureManager;
 class TextureRef;
 
@@ -170,6 +170,7 @@ class GPU_EXPORT Texture {
   }
 
  private:
+  friend class MailboxManager;
   friend class TextureManager;
   friend class TextureRef;
   friend class TextureTestHelper;
@@ -304,6 +305,8 @@ class GPU_EXPORT Texture {
       const FeatureInfo* feature_info,
       GLenum target, GLint level, std::string* signature) const;
 
+  void SetMailboxManager(MailboxManager* mailbox_manager);
+
   // Updates the unsafe textures count in all the managers referencing this
   // texture.
   void UpdateSafeToRenderFrom(bool cleared);
@@ -323,6 +326,8 @@ class GPU_EXPORT Texture {
   // referencing this texture.
   void IncAllFramebufferStateChangeCount();
 
+  MailboxManager* mailbox_manager_;
+
   // Info about each face and level of texture.
   std::vector<std::vector<LevelInfo> > level_infos_;
 
@@ -397,11 +402,13 @@ class GPU_EXPORT Texture {
 // Multiple TextureRef can point to the same texture with cross-context sharing.
 class GPU_EXPORT TextureRef : public base::RefCounted<TextureRef> {
  public:
-  TextureRef(TextureManager* manager, Texture* texture);
+  TextureRef(TextureManager* manager, GLuint client_id, Texture* texture);
   static scoped_refptr<TextureRef> Create(TextureManager* manager,
+                                          GLuint client_id,
                                           GLuint service_id);
   const Texture* texture() const { return texture_; }
   Texture* texture() { return texture_; }
+  GLuint client_id() const { return client_id_; }

[greggman, 2013/05/23 17:36:19]

I'm not sure I follow the need for this. Is it only for testing? Then there's
also the reset_client_id as well but there's still going to be a mapping from
client_id to TextureRef in textures_.  

[piman, 2013/05/23 18:02:38]

It's there to be able to do the Delete in Consume. We could go through the list,
but since we're likely going to Consume somewhat often on a context with many
textures, this seems heavy.

reset_client_id is called when we remove the TextureRef from textures_. That
way, if we delete the texture in one context and the texture is bound in
another, if we switch to the other context and call Consume, we won't try to
delete an unrelated texture (if the client id was reused in the mean time).

   GLuint service_id() const { return texture_->service_id(); }
 
   // Sets the async transfer state for this texture. Only a single TextureRef
@@ -424,9 +431,11 @@ class GPU_EXPORT TextureRef : public base::RefCounted<TextureRef> {
   AsyncPixelTransferState* async_transfer_state() const {
     return async_transfer_state_.get();
   }
+  void reset_client_id() { client_id_ = 0; }
 
   TextureManager* manager_;
   Texture* texture_;
+  GLuint client_id_;
 
   // State to facilitate async transfers on this texture.
   scoped_ptr<AsyncPixelTransferState> async_transfer_state_;
@@ -543,15 +552,10 @@ class GPU_EXPORT TextureManager {
         params.type, true /* cleared */ );
   }
 
-  // Save the texture definition and leave it undefined.
-  TextureDefinition* Save(TextureRef* ref);
+  Texture* Produce(TextureRef* ref);
 
-  // Redefine all the levels from the texture definition.
-  bool Restore(
-      const char* function_name,
-      GLES2Decoder* decoder,
-      TextureRef* ref,
-      TextureDefinition* definition);
+  // Maps an existing texture into the texture manager, at a given client ID.
+  TextureRef* Consume(GLuint client_id, Texture* texture);
 
   // Sets a mip as cleared.
   void SetLevelCleared(TextureRef* ref, GLenum target,