Create video and audio decoder threads on demand.

media/base/message_loop_factory_for_test.h

Index: media/base/message_loop_factory_for_test.h
diff --git a/media/base/message_loop_factory_for_test.h b/media/base/message_loop_factory_for_test.h
new file mode 100644
index 0000000000000000000000000000000000000000..7b0a0e9a3eee4bfa3b8f99c108e5b0c360050c48
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+++ b/media/base/message_loop_factory_for_test.h
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+// 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.
+
+#ifndef MEDIA_BASE_MESSAGE_LOOP_FACTORY_FOR_TEST_H_
+#define MEDIA_BASE_MESSAGE_LOOP_FACTORY_FOR_TEST_H_
+
+#include "base/compiler_specific.h"
+#include "media/base/message_loop_factory.h"
+
+namespace media {
+
+// A very basic implementation of MessageLoopFactory that supports only a single
+// loop.  Useful for tests that want to run video/audio decoders on the same
+// thread as the test runs on.
+class MessageLoopFactoryForTest : public MessageLoopFactory {
+ public:
+  explicit MessageLoopFactoryForTest(MessageLoop* the_only_loop);
+  virtual ~MessageLoopFactoryForTest();
+
+  virtual MessageLoop* GetMessageLoop(const std::string& name) OVERRIDE;
+
+ private:
+  MessageLoop* the_only_loop_;
+};
+
+}  // namespace media
+
+#endif  // MEDIA_BASE_MESSAGE_LOOP_FACTORY_FOR_TEST_H_