Prepare MediaDrmBridge to work with MediaCodecPlayer

media/base/android/media_task_runner.cc

+#include "media/base/android/media_task_runner.h"
+
+#include "base/command_line.h"
+#include "base/lazy_instance.h"
+#include "base/metrics/field_trial.h"
+#include "base/strings/string_util.h"
+#include "base/threading/thread.h"
+#include "media/base/media_switches.h"
+
+namespace media {
+
+class MediaThread : public base::Thread {
+ public:
+  MediaThread() : base::Thread("BrowserMediaThread") {
+    Start();
+  }
+};
+
+// Create media thread
+base::LazyInstance<MediaThread>::Leaky g_media_thread =
+    LAZY_INSTANCE_INITIALIZER;
+
+scoped_refptr<base::SingleThreadTaskRunner> GetMediaTaskRunner() {
+  return g_media_thread.Pointer()->task_runner();
+}
+
+bool UseMediaThreadForMediaPlayback() {
+  const std::string group_name =
+      base::FieldTrialList::FindFullName("EnableMediaThreadForMediaPlayback");
+
+  if (base::CommandLine::ForCurrentProcess()->
+      HasSwitch(switches::kEnableMediaThreadForMediaPlayback)) {
+    return true;
+  }
+
+  return base::StartsWith(group_name, "Enabled", base::CompareCase::SENSITIVE);
+}
+
+}  // namespace media