Create video and audio decoder threads on demand.

media/filters/ffmpeg_video_decoder_unittest.cc

Index: media/filters/ffmpeg_video_decoder_unittest.cc
diff --git a/media/filters/ffmpeg_video_decoder_unittest.cc b/media/filters/ffmpeg_video_decoder_unittest.cc
index ec583abebd1cd9dd432627cf668830369f85117b..34aa2365cb331f9b9301338eb4f00e0354299c8c 100644
--- a/media/filters/ffmpeg_video_decoder_unittest.cc
+++ b/media/filters/ffmpeg_video_decoder_unittest.cc
@@ -12,6 +12,7 @@
 #include "media/base/decrypt_config.h"
 #include "media/base/filters.h"
 #include "media/base/limits.h"
+#include "media/base/message_loop_factory_for_test.h"
 #include "media/base/mock_callback.h"
 #include "media/base/mock_filter_host.h"
 #include "media/base/mock_filters.h"
@@ -48,10 +49,13 @@ ACTION_P(ReturnBuffer, buffer) {
 class FFmpegVideoDecoderTest : public testing::Test {
  public:
   FFmpegVideoDecoderTest()
-      : decoder_(new FFmpegVideoDecoder(&message_loop_)),
-        demuxer_(new StrictMock<MockDemuxerStream>()),
-        read_cb_(base::Bind(&FFmpegVideoDecoderTest::FrameReady,
+      : read_cb_(base::Bind(&FFmpegVideoDecoderTest::FrameReady,
                             base::Unretained(this))) {
+    message_loop_factory_.reset(new MessageLoopFactoryForTest(&message_loop_));
+    decoder_ = new FFmpegVideoDecoder(message_loop_factory_.get(),
+                                      "VideoDecoderThread");
+    demuxer_ = new StrictMock<MockDemuxerStream>();
+
     CHECK(FFmpegGlue::GetInstance());
 
     decoder_->set_host(&host_);
@@ -195,6 +199,7 @@ class FFmpegVideoDecoderTest : public testing::Test {
 
   MOCK_METHOD1(FrameReady, void(scoped_refptr<VideoFrame>));
 
+  scoped_ptr<MessageLoopFactory> message_loop_factory_;
   MessageLoop message_loop_;
   scoped_refptr<FFmpegVideoDecoder> decoder_;
   scoped_refptr<StrictMock<MockDemuxerStream> > demuxer_;