media: Make MediaKeys ref-counted.

content/browser/media/android/media_drm_credential_manager.cc

 // Copyright 2013 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 "content/browser/media/android/media_drm_credential_manager.h"
 
 #include "base/android/jni_android.h"
 #include "base/android/scoped_java_ref.h"
 #include "base/bind.h"
 #include "base/callback_helpers.h"
@@ skipping 67 matching lines @@
 
 void MediaDrmCredentialManager::OnResetCredentialsCompleted(
     SecurityLevel security_level, bool success) {
   if (security_level == media::MediaDrmBridge::SECURITY_LEVEL_3 && success) {
     if (ResetCredentialsInternal(media::MediaDrmBridge::SECURITY_LEVEL_1))
       return;
     success = false;
   }
 
   base::ResetAndReturn(&reset_credentials_cb_).Run(success);
-  media_drm_bridge_.reset();
+  media_drm_bridge_ = nullptr;
 }
 
 // TODO(ddorwin): The key system should be passed in. http://crbug.com/459400
 bool MediaDrmCredentialManager::ResetCredentialsInternal(
     SecurityLevel security_level) {
   media_drm_bridge_ =
       media::MediaDrmBridge::CreateWithoutSessionSupport(kWidevineKeySystem);
   if (!media_drm_bridge_)
     return false;
 
@@ skipping 11 matching lines @@
   media_drm_bridge_->ResetDeviceCredentials(reset_credentials_cb);
   return true;
 }
 
 // static
 bool MediaDrmCredentialManager::RegisterMediaDrmCredentialManager(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace content