Intiialize AudioManager and related class lazily

media/audio/android/audio_manager_android.cc

Index: media/audio/android/audio_manager_android.cc
diff --git a/media/audio/android/audio_manager_android.cc b/media/audio/android/audio_manager_android.cc
index a7ec08d69c4d30e60b56716a450f43ae8c1e6b86..02881688bc672e5a5807208d1f23ea6811203e0e 100644
--- a/media/audio/android/audio_manager_android.cc
+++ b/media/audio/android/audio_manager_android.cc
@@ -63,30 +63,39 @@ AudioManagerAndroid::AudioManagerAndroid(
                        audio_log_factory),
       communication_mode_is_on_(false),
       output_volume_override_set_(false),
-      output_volume_override_(0) {
+      output_volume_override_(0),
+      initialized_(false) {
   SetMaxOutputStreamsAllowed(kMaxOutputStreams);
-
-  // WARNING: This is executed on the UI loop, do not add any code here which
-  // loads libraries or attempts to call out into the OS.  Instead add such code
-  // to the InitializeOnAudioThread() method below.
-
-  // Task must be posted last to avoid races from handing out "this" to the
-  // audio thread.
-  GetTaskRunner()->PostTask(FROM_HERE, base::Bind(
-      &AudioManagerAndroid::InitializeOnAudioThread,
-      base::Unretained(this)));
 }
 
 AudioManagerAndroid::~AudioManagerAndroid() {
   DCHECK(GetTaskRunner()->BelongsToCurrentThread());
   Shutdown();
 
+  if (j_audio_manager_.is_null())
+    return;
   DVLOG(2) << "Destroying Java part of the audio manager";
   Java_AudioManagerAndroid_close(base::android::AttachCurrentThread(),
                                  j_audio_manager_.obj());
   j_audio_manager_.Reset();
 }
 
+void AudioManagerAndroid::InitializeIfNeeded() {
+  if (initialized_)
+    return;
+
+  // WARNING: This is executed on the UI loop, do not add any code here which
+  // loads libraries or attempts to call out into the OS. Instead add such code
+  // to the InitializeOnAudioThread() method below.
+
+  // Task must be posted last to avoid races from handing out "this" to the
+  // audio thread.
+  GetTaskRunner()->PostTask(FROM_HERE, base::Bind(
+      &AudioManagerAndroid::InitializeOnAudioThread,
+      base::Unretained(this)));
+  initialized_ = true;
+}
+
 bool AudioManagerAndroid::HasAudioOutputDevices() {
   return true;
 }