Implement "Key Presence" step in "Encrypted Block Encounted" algorithm in EME.

media/filters/chunk_demuxer_unittest.cc

 // Copyright (c) 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 "base/bind.h"
+#include "base/message_loop.h"
 #include "media/base/audio_decoder_config.h"
 #include "media/base/decoder_buffer.h"
 #include "media/base/mock_callback.h"
 #include "media/base/mock_demuxer_host.h"
 #include "media/base/test_data_util.h"
 #include "media/filters/chunk_demuxer.h"
 #include "media/filters/chunk_demuxer_client.h"
 #include "media/webm/cluster_builder.h"
 #include "media/webm/webm_constants.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 646 matching lines @@
                                    timestamps[i].video_time_ms),
                                &video_read_done));
 
         EXPECT_TRUE(video_read_done);
       }
     }
 
     return true;
   }
 
+  MessageLoop message_loop_;

[xhwang, 2012/07/30 20:48:25]

In the original test, since we don't have a message loop, MessageLoop::Current()
returns NULL. The test still works because it compares pointers directly (i.e.
if (NULL != NULL) ...):
http://code.google.com/searchframe#OAMlx_jo-ck/src/media/filters/chunk_demuxe...

But now we switch to MessageLoopProxy, this is caught by an assertion:
T* scoped_refptr<T>::operator->() const [with T = base::MessageLoopProxy]:
Assertion `ptr_ != __null' failed.

It makes sense for me to create a MessageLoop here so that we don't rely on the
"if (NULL != NULL)" logic. With this, all tests pass now.

   MockDemuxerHost host_;
 
   scoped_ptr<MockChunkDemuxerClient> client_;
   scoped_refptr<ChunkDemuxer> demuxer_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ChunkDemuxerTest);
 };
 
 TEST_F(ChunkDemuxerTest, TestInit) {
@@ skipping 1442 matching lines @@
   ASSERT_TRUE(InitDemuxer(true, true, false));
 
   scoped_ptr<Cluster> cluster = GenerateCluster(0, 2);
   // Append only part of the cluster data.
   ASSERT_TRUE(AppendData(cluster->data(), cluster->size() - 13));
 
   // Setting a timestamp should fail because we're in the middle of a cluster.
   ASSERT_FALSE(demuxer_->SetTimestampOffset(kSourceId, 25));
 }
 }  // namespace media