cc: Update Main RendererCapabilities on DeferredInitialize

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 "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/location.h"
 #include "base/synchronization/lock.h"
@@ skipping 19 matching lines @@
       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),
       blend_background_color_(false),
       rate_limit_context_(false),
       content_committed_(false),
       texture_id_(0),
-      needs_set_mailbox_(false) {
+      needs_set_mailbox_(false),
+      did_use_shared_memory_resources_(false) {
   vertex_opacity_[0] = 1.0f;
   vertex_opacity_[1] = 1.0f;
   vertex_opacity_[2] = 1.0f;
   vertex_opacity_[3] = 1.0f;
 }
 
 TextureLayer::~TextureLayer() {
 }
 
 void TextureLayer::ClearClient() {
@@ skipping 163 matching lines @@
 
 bool TextureLayer::DrawsContent() const {
   return (client_ || texture_id_ || holder_ref_) && Layer::DrawsContent();
 }
 
 bool TextureLayer::Update(ResourceUpdateQueue* queue,
                           const OcclusionTracker* occlusion) {
   bool updated = Layer::Update(queue, occlusion);
   if (client_) {
     if (uses_mailbox_) {
+      bool use_shared_memory_resources =
+          layer_tree_host()->UsingSharedMemoryResources();
+      if (did_use_shared_memory_resources_ != use_shared_memory_resources) {
+        holder_ref_.reset();

[danakj, 2014/02/14 19:38:50]

Now that we're here, I wonder.. the call to PrepareTextureMailbox will tell the
client about UsingSharedMemoryResources. If they set a new (or empty) TM as a
result, it'll reset the holder ref. So what is this buying us? Is it saving us
redundant code in other places?

[boliu, 2014/02/14 22:03:08]

Good point...removed all this code and just make the client a little bit
smarter.

+      }
+      did_use_shared_memory_resources_ = use_shared_memory_resources;
+
       TextureMailbox mailbox;
       scoped_ptr<SingleReleaseCallback> release_callback;
       if (client_->PrepareTextureMailbox(
               &mailbox,
               &release_callback,
               layer_tree_host()->UsingSharedMemoryResources())) {
         // Already within a commit, no need to do another one immediately.
         SetTextureMailboxInternal(
             mailbox,
             release_callback.Pass(),
@@ skipping 117 matching lines @@
 
 void TextureLayer::TextureMailboxHolder::ReturnAndReleaseOnImplThread(
     uint32 sync_point,
     bool is_lost) {
   Return(sync_point, is_lost);
   message_loop_->PostTask(
       FROM_HERE, base::Bind(&TextureMailboxHolder::InternalRelease, this));
 }
 
 }  // namespace cc