Prepare MediaDrmBridge to work with MediaCodecPlayer

media/cdm/player_tracker_impl.cc

 // Copyright 2014 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.
 
 #include "media/cdm/player_tracker_impl.h"
 
 #include <utility>
 
 #include "base/stl_util.h"
 
 namespace media {
 
 PlayerTrackerImpl::PlayerCallbacks::PlayerCallbacks(
     base::Closure new_key_cb,
     base::Closure cdm_unset_cb)
     : new_key_cb(new_key_cb), cdm_unset_cb(cdm_unset_cb) {
 }
 
 PlayerTrackerImpl::PlayerCallbacks::~PlayerCallbacks() {
 }
 
-PlayerTrackerImpl::PlayerTrackerImpl() : next_registration_id_(1) {}
+PlayerTrackerImpl::PlayerTrackerImpl() : next_registration_id_(1) {
+  // Enable PlayerTrackerImpl to be created on another thread than it will be
+  // later exclusively used.
+  thread_checker_.DetachFromThread();
+}
 
 PlayerTrackerImpl::~PlayerTrackerImpl() {}
 
 int PlayerTrackerImpl::RegisterPlayer(const base::Closure& new_key_cb,
                                       const base::Closure& cdm_unset_cb) {
   DCHECK(thread_checker_.CalledOnValidThread());
   int registration_id = next_registration_id_++;
   DCHECK(!ContainsKey(player_callbacks_map_, registration_id));
   player_callbacks_map_.insert(std::make_pair(
       registration_id, PlayerCallbacks(new_key_cb, cdm_unset_cb)));
@@ skipping 15 matching lines @@
 }
 
 void PlayerTrackerImpl::NotifyCdmUnset() {
   DCHECK(thread_checker_.CalledOnValidThread());
   std::map<int, PlayerCallbacks>::iterator iter = player_callbacks_map_.begin();
   for (; iter != player_callbacks_map_.end(); ++iter)
     iter->second.cdm_unset_cb.Run();
 }
 
 }  // namespace media