Create video and audio decoder threads on demand.

media/filters/ffmpeg_audio_decoder_unittest.cc

Index: media/filters/ffmpeg_audio_decoder_unittest.cc
diff --git a/media/filters/ffmpeg_audio_decoder_unittest.cc b/media/filters/ffmpeg_audio_decoder_unittest.cc
index eb634c7926b6f7f5d2e4cf33bc3436473604c26c..6c6a1247ff9f19054d25020d037b7db731f936d1 100644
--- a/media/filters/ffmpeg_audio_decoder_unittest.cc
+++ b/media/filters/ffmpeg_audio_decoder_unittest.cc
@@ -8,6 +8,7 @@
 #include "base/message_loop.h"
 #include "base/stringprintf.h"
 #include "media/base/data_buffer.h"
+#include "media/base/message_loop_factory_for_test.h"
 #include "media/base/mock_callback.h"
 #include "media/base/mock_filters.h"
 #include "media/base/test_data_util.h"
@@ -28,9 +29,11 @@ ACTION_P(InvokeReadPacket, test) {
 
 class FFmpegAudioDecoderTest : public testing::Test {
  public:
-  FFmpegAudioDecoderTest()
-      : decoder_(new FFmpegAudioDecoder(&message_loop_)),
-        demuxer_(new StrictMock<MockDemuxerStream>()) {
+  FFmpegAudioDecoderTest() {
+    message_loop_factory_.reset(new MessageLoopFactoryForTest(&message_loop_));
+    demuxer_ = new StrictMock<MockDemuxerStream>();
+    decoder_ = new FFmpegAudioDecoder(message_loop_factory_.get(),
+                                      "AudioDecoderThread");
     CHECK(FFmpegGlue::GetInstance());
 
     ReadTestDataFile("vorbis-extradata",
@@ -110,6 +113,7 @@ class FFmpegAudioDecoderTest : public testing::Test {
     EXPECT_TRUE(decoded_audio_[i]->IsEndOfStream());
   }
 
+  scoped_ptr<MessageLoopFactory> message_loop_factory_;
   MessageLoop message_loop_;
   scoped_refptr<FFmpegAudioDecoder> decoder_;
   scoped_refptr<StrictMock<MockDemuxerStream> > demuxer_;