Revert of [media] Replace MessageLoopProxy usage with ThreadTaskRunnerHandle

media/blink/webcontentdecryptionmoduleaccess_impl.cc

Index: media/blink/webcontentdecryptionmoduleaccess_impl.cc
diff --git a/media/blink/webcontentdecryptionmoduleaccess_impl.cc b/media/blink/webcontentdecryptionmoduleaccess_impl.cc
index a72cbff3c991ed0521dc85b8eea2bc4d0b5c0fb7..5c28234827d1c87946a7da493451a568ea7ad29b 100644
--- a/media/blink/webcontentdecryptionmoduleaccess_impl.cc
+++ b/media/blink/webcontentdecryptionmoduleaccess_impl.cc
@@ -6,8 +6,7 @@
 
 #include "base/bind.h"
 #include "base/location.h"
-#include "base/single_thread_task_runner.h"
-#include "base/thread_task_runner_handle.h"
+#include "base/message_loop/message_loop_proxy.h"
 #include "media/blink/webencryptedmediaclient_impl.h"
 
 namespace media {
@@ -80,7 +79,7 @@
   // As this object's lifetime is controlled by MediaKeySystemAccess on the
   // blink side, copy all values needed by CreateCdm() in case the blink object
   // gets garbage-collected.
-  base::ThreadTaskRunnerHandle::Get()->PostTask(
+  base::MessageLoopProxy::current()->PostTask(
       FROM_HERE,
       base::Bind(&CreateCdm, client_, key_system_, allow_distinctive_identifier,
                  allow_persistent_state, security_origin_, result));