Allow WebExternalTextureLayerClient to work with mailboxes.

cc/texture_layer.cc

 // Copyright 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/texture_layer.h"
 
 #include "cc/layer_tree_host.h"
 #include "cc/texture_layer_client.h"
 #include "cc/texture_layer_impl.h"
 #include "cc/thread.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebGraphicsContext3D.h"
 
 namespace cc {
 
 static void RunCallbackOnMainThread(
     const TextureMailbox::ReleaseCallback& callback,
     unsigned sync_point) {
   callback.Run(sync_point);
 }
 
 static void PostCallbackToMainThread(
     Thread* main_thread,
     const TextureMailbox::ReleaseCallback& callback,
     unsigned sync_point) {
   main_thread->postTask(
       base::Bind(&RunCallbackOnMainThread, callback, sync_point));
 }
 
-scoped_refptr<TextureLayer> TextureLayer::Create(TextureLayerClient* client) {
-  return scoped_refptr<TextureLayer>(new TextureLayer(client, false));
-}
-
-scoped_refptr<TextureLayer> TextureLayer::CreateForMailbox() {
-  return scoped_refptr<TextureLayer>(new TextureLayer(NULL, true));
+scoped_refptr<TextureLayer> TextureLayer::Create(TextureLayerClient* client,
+                                                 bool usesMailbox) {

[piman, 2013/03/14 19:54:58]

nit: uses_mailbox

[alexst (slow to review), 2013/03/14 20:37:06]

Done.

+  return scoped_refptr<TextureLayer>(new TextureLayer(client, usesMailbox));
 }
 
 TextureLayer::TextureLayer(TextureLayerClient* client, bool uses_mailbox)
     : Layer(),
       client_(client),
       uses_mailbox_(uses_mailbox),
       flipped_(true),
       uv_top_left_(0.f, 0.f),
       uv_bottom_right_(1.f, 1.f),
       premultiplied_alpha_(true),
@@ skipping 106 matching lines @@
 
 bool TextureLayer::DrawsContent() const {
   return (client_ || texture_id_ || !texture_mailbox_.IsEmpty()) &&
          !context_lost_ && Layer::DrawsContent();
 }
 
 void TextureLayer::Update(ResourceUpdateQueue* queue,
                           const OcclusionTracker* occlusion,
                           RenderingStats* stats) {
   if (client_) {
-    texture_id_ = client_->prepareTexture(*queue);
+    if (uses_mailbox_) {
+      TextureMailbox mailbox;
+      if (client_->prepareTextureMailbox(&mailbox))
+        SetTextureMailbox(mailbox);

[piman, 2013/03/14 19:54:58]

How hard would it be to change the BrowserPluginCompositingHelper to use the
TextureLayerClient::prepareTextureMailbox path, and then make SetTextureMailbox
private? It would be nice to have a single mailbox path.

As we remove the non-mailbox users, I'm sure we can shortly remove the
SetTextureId path, and possibly even the non-mailbox paths in a nearish future -
basically streamlining the code paths.

[alexst (slow to review), 2013/03/14 20:37:06]

Shouldn't be too bad, I'll look into it.

As far as removing SetTextureId path, once the rest of the canvas code is using
mailboxes, I think browser compositor is the last user, so it should be doable.

+    } else {
+      texture_id_ = client_->prepareTexture(*queue);
+    }
     context_lost_ =
         client_->context()->getGraphicsResetStatusARB() != GL_NO_ERROR;
   }
 
   needs_display_ = false;
 }
 
 void TextureLayer::PushPropertiesTo(LayerImpl* layer) {
   Layer::PushPropertiesTo(layer);
 
@@ skipping 23 matching lines @@
   // triple-buffered.  Single-buffered layers already prevent draws, so
   // can block too for simplicity.
   return DrawsContent();
 }
 
 bool TextureLayer::CanClipSelf() const {
   return true;
 }
 
 }  // namespace cc