Win AEC: Handle SetOutputDeviceForAec being called before Start()

When using APM in Audio Service, the output device for a microphone
with native echo cancellation support may be set before the stream
has started. For the Windows AEC implementation, this would start
the dummy output stream, which is used to ensure a continuous
reverse stream, too early.

Bug: 882420
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Change-Id: I1121cc4b35a0457f006326dfc0340379f9a0e091
Reviewed-on: https://chromium-review.googlesource.com/1243088
Commit-Queue: Oskar Sundbom <ossu@chromium.org>
Reviewed-by: Henrik Grunell <grunell@chromium.org>
Reviewed-by: Olga Sharonova <olka@chromium.org>
Cr-Commit-Position: refs/heads/master@{#594685}

media/audio/win/audio_low_latency_input_win.cc

@@ -532,12 +532,14 @@ void WASAPIAudioInputStream::SetOutputDeviceForAec(
 
   output_device_id_for_aec_ = output_device_id;
 
+  if (opened_) {
     // Set devices.
     Microsoft::WRL::ComPtr<IPropertyStore> ps;
     HRESULT hr = voice_capture_dmo_->QueryInterface(IID_IPropertyStore, &ps);
     if (FAILED(hr) || !ps) {
-    log_callback_.Run(base::StringPrintf(
-        "WASAPIAIS:SetOutputDeviceForAec: Getting DMO property store failed."));
+      log_callback_.Run(
+          base::StringPrintf("WASAPIAIS:SetOutputDeviceForAec: Getting DMO "
+                             "property store failed."));
       return;
     }
 
@@ -546,9 +548,12 @@ void WASAPIAudioInputStream::SetOutputDeviceForAec(
           "WASAPIAIS:SetOutputDeviceForAec: Setting device indices failed.");
       return;
     }
+  }
 
+  if (started_) {
+    DCHECK(opened_);
     // Recreate the dummy render client on the new output.
-  hr = audio_client_for_render_->Stop();
+    HRESULT hr = audio_client_for_render_->Stop();
     if (FAILED(hr)) {
       DLOG(ERROR) << "Failed to stop output streaming.";
     }
@@ -565,6 +570,7 @@ void WASAPIAudioInputStream::SetOutputDeviceForAec(
       DLOG(ERROR) << "Failed to start output streaming: " << std::hex << hr
                   << ", proceeding without rendering.";
     }
+  }
 
   log_callback_.Run(base::StringPrintf(
       "WASAPIAIS:SetOutputDeviceForAec: Successfully updated AEC output "