Add UMA to check whether requestAudioFocus() is successful.

content/browser/media/android/media_session.cc

 // Copyright 2015 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_session.h"
 
 #include "base/android/context_utils.h"
 #include "base/android/jni_android.h"
 #include "content/browser/media/android/media_session_observer.h"
 #include "content/browser/web_contents/web_contents_impl.h"
@@ skipping 270 matching lines @@
       reinterpret_cast<intptr_t>(this)));
 }
 
 bool MediaSession::RequestSystemAudioFocus(Type type) {
   // During tests, j_media_session_ might be null.
   if (j_media_session_.is_null())
     return true;
 
   JNIEnv* env = base::android::AttachCurrentThread();
   DCHECK(env);
-  return Java_MediaSession_requestAudioFocus(env, j_media_session_.obj(),
-                                             type == Type::Transient);
+  bool result = Java_MediaSession_requestAudioFocus(env, j_media_session_.obj(),
+                                                    type == Type::Transient);
+  uma_helper_.RecordRequestAudioFocusResult(result);
+  return result;
 }
 
 void MediaSession::AbandonSystemAudioFocusIfNeeded() {
   if (audio_focus_state_ == State::INACTIVE || !players_.empty())
     return;
 
   // During tests, j_media_session_ might be null.
   if (!j_media_session_.is_null()) {
     JNIEnv* env = base::android::AttachCurrentThread();
     DCHECK(env);
@@ skipping 20 matching lines @@
     case State::SUSPENDED:
       uma_helper_.OnSessionSuspended();
       break;
     case State::INACTIVE:
       uma_helper_.OnSessionInactive();
       break;
   }
 }
 
 }  // namespace content