Allow WebExternalTextureLayers to receive a bitmap along with a mailbox

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 141 matching lines @@
   SetNeedsCommit();
 }
 
 void TextureLayer::WillModifyTexture() {
   if (layer_tree_host() && (DrawsContent() || content_committed_)) {
     layer_tree_host()->AcquireLayerTextures();
     content_committed_ = false;
   }
 }
 
+bool TextureLayer::MustUseBitmap() {
+  return layer_tree_host()->UsingSoftwareRenderer();
+}
+
 void TextureLayer::SetNeedsDisplayRect(const gfx::RectF& dirty_rect) {
   Layer::SetNeedsDisplayRect(dirty_rect);
 
   if (rate_limit_context_ && client_ && layer_tree_host() && DrawsContent())
     layer_tree_host()->StartRateLimiter(client_->Context3d());
 }
 
 void TextureLayer::SetLayerTreeHost(LayerTreeHost* host) {
   if (texture_id_ && layer_tree_host() && host != layer_tree_host())
     layer_tree_host()->AcquireLayerTextures();
@@ skipping 79 matching lines @@
 TextureLayer::MailboxHolder::~MailboxHolder() {
   mailbox_.RunReleaseCallback(sync_point_, is_lost_);
 }
 
 void TextureLayer::MailboxHolder::Return(unsigned sync_point, bool is_lost) {
   sync_point_ = sync_point;
   is_lost_ = is_lost;
 }
 
 }  // namespace cc