Fix hotword module constantly restarting on Pixel 2.

content/renderer/media/user_media_client_impl.cc

Index: content/renderer/media/user_media_client_impl.cc
diff --git a/content/renderer/media/user_media_client_impl.cc b/content/renderer/media/user_media_client_impl.cc
index 15e096b6469d9b1bc061d68be7d41c99bb18666c..faf827456d79393dea5a25196afdbacb2a66065c 100644
--- a/content/renderer/media/user_media_client_impl.cc
+++ b/content/renderer/media/user_media_client_impl.cc
@@ -69,8 +69,11 @@ void CopyBlinkRequestToStreamControls(const blink::WebUserMediaRequest& request,
     // TODO(hta): Get alternatives only mentioned in advanced array.
     CopyVector(audio_basic.deviceId.ideal(),
                &controls->audio.alternate_device_ids);
-    if (!audio_basic.hotwordEnabled.matches(false))
-      controls->hotword_enabled = true;
+
+    for (const auto& audio_advanced : request.audioConstraints().advanced()) {
+      if (!audio_advanced.hotwordEnabled.matches(false))
+        controls->hotword_enabled = true;

[hta - Chromium, 2016/02/26 11:35:44]

1) put a break in this loop.

2) instead use
  if (audio_basic.hasExact()) {
     controls->hotword_enabled =    
        audio_advanced.hotwordEnabled.exact();
  } else {
    if(audio_advanced.hotwordEnabled.hasExact()) {
     controls->hotword_enabled =      
         audio_advanced.hotwordEnabled.exact();
     break;
  }

Yes, there's an utility function to do this, but it's in a CL that hasn't been
submitted yet :-(

3) write an unit test!

[Anand Mistry (off Chromium), 2016/02/29 02:10:07]

Done.
Done.
And there's the problem. It looks like this code doesn't have any unit tests. In
fact, I'm not sure I can write any unit tests given this nugget of comment in
UserMediaClientImpl::requestUserMedia():
// |user_media_request| can't be mocked. So in order to test at all we check
// if it isNull.

+    }
   }
   if (!request.videoConstraints().isNull()) {
     const blink::WebMediaTrackConstraintSet& video_basic =