cc: Allow pepper to avoid DCHECK but reuse gpu::Mailbox.

cc/layers/texture_layer_unittest.cc

 // Copyright 2012 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 <algorithm>
 #include <string>
 
 #include "base/bind.h"
@@ skipping 441 matching lines @@
   Mock::VerifyAndClearExpectations(layer_tree_host_.get());
   Mock::VerifyAndClearExpectations(&test_data_.mock_callback_);
 
   // Test destructor.
   EXPECT_CALL(*layer_tree_host_, SetNeedsCommit()).Times(AtLeast(1));
   test_layer->SetTextureMailbox(
       test_data_.mailbox1_,
       SingleReleaseCallback::Create(test_data_.release_mailbox1_));
 }
 
+TEST_F(TextureLayerTest, SetTextureMailboxWithoutReleaseCallback) {
+  scoped_refptr<TextureLayer> test_layer = TextureLayer::CreateForMailbox(NULL);
+  ASSERT_TRUE(test_layer.get());
+
+  // These use the same gpu::Mailbox, but different sync points.
+  TextureMailbox mailbox1(MailboxFromChar('a'), GL_TEXTURE_2D, 1);
+  TextureMailbox mailbox2(MailboxFromChar('a'), GL_TEXTURE_2D, 2);
+
+  EXPECT_CALL(*layer_tree_host_, AcquireLayerTextures()).Times(0);
+  EXPECT_CALL(*layer_tree_host_, SetNeedsCommit()).Times(AnyNumber());
+  layer_tree_host_->SetRootLayer(test_layer);
+  Mock::VerifyAndClearExpectations(layer_tree_host_.get());
+
+  // Set the mailbox the first time. It should cause a commit.
+  EXPECT_CALL(*layer_tree_host_, AcquireLayerTextures()).Times(0);
+  EXPECT_CALL(*layer_tree_host_, SetNeedsCommit()).Times(AtLeast(1));
+  test_layer->SetTextureMailboxWithoutReleaseCallback(mailbox1);
+  Mock::VerifyAndClearExpectations(layer_tree_host_.get());
+
+  // Set the mailbox again with a new sync point, as the backing texture has
+  // been updated. It should cause a new commit.
+  EXPECT_CALL(*layer_tree_host_, AcquireLayerTextures()).Times(0);
+  EXPECT_CALL(*layer_tree_host_, SetNeedsCommit()).Times(AtLeast(1));
+  test_layer->SetTextureMailboxWithoutReleaseCallback(mailbox2);
+  Mock::VerifyAndClearExpectations(layer_tree_host_.get());
+}
+
 class TextureLayerMailboxHolderTest : public TextureLayerTest {
  public:
   TextureLayerMailboxHolderTest()
       : main_thread_("MAIN") {
     main_thread_.Start();
   }
 
   void Wait(const base::Thread& thread) {
     bool manual_reset = false;
     bool initially_signaled = false;
@@ skipping 1692 matching lines @@
   int callback_count_;
   scoped_refptr<Layer> root_;
   scoped_refptr<TextureLayer> layer_;
 };
 
 SINGLE_AND_MULTI_THREAD_DIRECT_RENDERER_TEST_F(
     TextureLayerWithMailboxImplThreadDeleted);
 
 }  // namespace
 }  // namespace cc