Introduce AudioRendererSink::IsOptimizedForHardwareParameters

media/blink/webaudiosourceprovider_impl.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 "media/blink/webaudiosourceprovider_impl.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
@@ skipping 240 matching lines @@
     sink_->SetVolume(volume);
   return true;
 }
 
 OutputDeviceInfo WebAudioSourceProviderImpl::GetOutputDeviceInfo() {
   base::AutoLock auto_lock(sink_lock_);
   return sink_ ? sink_->GetOutputDeviceInfo()
                : OutputDeviceInfo(OUTPUT_DEVICE_STATUS_ERROR_NOT_FOUND);
 }
 
+bool WebAudioSourceProviderImpl::IsOptimizedForHardwareParameters() {
+  return client_ ? false : true;

[o1ka, 2017/05/16 10:31:19]

Access to |client_| is guarded everywhere by |sink_lock_|.
Is data race intentional here? Or is it not possible?
I would prefer to avoid locking here if we can, because we've had troubles with
that lock before (around l.119). But then we need a comment explaining what's
going on.

[flim-chromium, 2017/05/16 11:04:05]

Thanks for spotting this! I think it would actually be safer to add the lock; I
can't see a guarantee that there won't be a race with SetClient. If that also
makes sense to you, I'll upload the change.

+}
+
 bool WebAudioSourceProviderImpl::CurrentThreadIsRenderingThread() {
   NOTIMPLEMENTED();
   return false;
 }
 
 void WebAudioSourceProviderImpl::SwitchOutputDevice(
     const std::string& device_id,
     const url::Origin& security_origin,
     const OutputDeviceStatusCB& callback) {
   base::AutoLock auto_lock(sink_lock_);
@@ skipping 61 matching lines @@
 
   return num_rendered_frames;
 }
 
 void WebAudioSourceProviderImpl::TeeFilter::OnRenderError() {
   DCHECK(IsInitialized());
   renderer_->OnRenderError();
 }
 
 }  // namespace media