Allow WebExternalTextureLayerClient to work with mailboxes.

cc/layers/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/layers/texture_layer.h"
 
 #include "cc/base/thread.h"
 #include "cc/layers/texture_layer_client.h"
 #include "cc/layers/texture_layer_impl.h"
 #include "cc/trees/layer_tree_host.h"
@@ skipping 12 matching lines @@
     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::CreateForMailbox(
+    TextureLayerClient* client) {
+  return scoped_refptr<TextureLayer>(new TextureLayer(client, true));
 }
 
 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 14 matching lines @@
       layer_tree_host()->AcquireLayerTextures();
     if (rate_limit_context_ && client_)
       layer_tree_host()->StopRateLimiter(client_->Context3d());
   }
   if (own_mailbox_)
     texture_mailbox_.RunReleaseCallback(texture_mailbox_.sync_point());
 }
 
 void TextureLayer::ClearClient() {
   client_ = NULL;
-  SetTextureId(0);
+  if (uses_mailbox_)
+    SetTextureMailbox(TextureMailbox());
+  else
+    SetTextureId(0);
 }
 
 scoped_ptr<LayerImpl> TextureLayer::CreateLayerImpl(LayerTreeImpl* tree_impl) {
   return TextureLayerImpl::Create(tree_impl, id(), uses_mailbox_).
       PassAs<LayerImpl>();
 }
 
 void TextureLayer::SetFlipped(bool flipped) {
   flipped_ = flipped;
   SetNeedsCommit();
@@ skipping 76 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);
+    } else {
+      texture_id_ = client_->PrepareTexture(queue);
+    }
     context_lost_ =
         client_->Context3d()->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