Improve input handling for WaveAudioHandler.

media/audio/sounds/sounds_manager.cc

Index: media/audio/sounds/sounds_manager.cc
diff --git a/media/audio/sounds/sounds_manager.cc b/media/audio/sounds/sounds_manager.cc
index 17f0dd874368f89c23c2aab57749e9c771b8282f..9774ce8f7a1a0aa9483541fc9c65060a4ae82bb9 100644
--- a/media/audio/sounds/sounds_manager.cc
+++ b/media/audio/sounds/sounds_manager.cc
@@ -64,19 +64,13 @@ bool SoundsManagerImpl::Initialize(SoundKey key,
 bool SoundsManagerImpl::Play(SoundKey key) {
   DCHECK(CalledOnValidThread());
   linked_ptr<AudioStreamHandler> handler = GetHandler(key);
-  if (!handler.get())
-    return false;
-  if (!handler->IsInitialized())
-    return false;
-  return handler->Play();
+  return handler.get() && handler->IsInitialized() && handler->Play();
 }
 
 bool SoundsManagerImpl::Stop(SoundKey key) {
   DCHECK(CalledOnValidThread());
   linked_ptr<AudioStreamHandler> handler = GetHandler(key);
-  if (!handler.get())
-    return false;
-  if (!handler->IsInitialized())
+  if (!handler.get() || !handler->IsInitialized())
     return false;
   handler->Stop();
   return true;
@@ -85,12 +79,9 @@ bool SoundsManagerImpl::Stop(SoundKey key) {
 base::TimeDelta SoundsManagerImpl::GetDuration(SoundKey key) {
   DCHECK(CalledOnValidThread());
   linked_ptr<AudioStreamHandler> handler = GetHandler(key);
-  if (!handler.get())
+  if (!handler.get() || !handler->IsInitialized())
       return base::TimeDelta();
-  if (!handler->IsInitialized())
-    return base::TimeDelta();
-  const WavAudioHandler& wav_audio = handler->wav_audio_handler();
-  return wav_audio.GetDuration();
+  return handler->duration();
 }
 
 linked_ptr<AudioStreamHandler> SoundsManagerImpl::GetHandler(SoundKey key) {