Added stub MediaSourcePlayer for developing behind the flag

base/threading/non_thread_safe.h

Index: base/threading/non_thread_safe.h
diff --git a/base/threading/non_thread_safe.h b/base/threading/non_thread_safe.h
index d41c08608c96a12d17c7a4d0da40d52607f81854..ea6d32c3a13e22ba155fe872d508e9e70c57169d 100644
--- a/base/threading/non_thread_safe.h
+++ b/base/threading/non_thread_safe.h
@@ -58,7 +58,9 @@ class NonThreadSafeDoNothing {
 // to have a base::ThreadChecker as a member, rather than inherit from
 // NonThreadSafe. For more details about when to choose one over the other, see
 // the documentation for base::ThreadChecker.
-#if ENABLE_NON_THREAD_SAFE
+#if defined(DISABLE_NON_THREAD_SAFE)
+typedef NonThreadSafeDoNothing NonThreadSafe;

[timav, 2015/04/23 23:06:12]

Another problem discovered later with the real implementation is that IDMap in
android demuxer complains about the wrong threads. I did not want to modify this
file, but could not find the way around.

+#elif defined(ENABLE_NON_THREAD_SAFE)
 typedef NonThreadSafeImpl NonThreadSafe;
 #else
 typedef NonThreadSafeDoNothing NonThreadSafe;