UMA stats for browser/renderer audio rendering buffer size mismatch.

media/base/audio_parameters.cc

Index: media/base/audio_parameters.cc
diff --git a/media/base/audio_parameters.cc b/media/base/audio_parameters.cc
index c40a7aa0d4094657ae308945580fa2bd9b58ec13..e3f9bb514257707935dbbe3bdbfd7f7ed3c330d5 100644
--- a/media/base/audio_parameters.cc
+++ b/media/base/audio_parameters.cc
@@ -16,7 +16,8 @@ AudioParameters::AudioParameters(Format format,
                                  ChannelLayout channel_layout,
                                  int sample_rate,
                                  int bits_per_sample,
-                                 int frames_per_buffer) {
+                                 int frames_per_buffer)
+    : latency_tag_(AudioLatency::LATENCY_COUNT) {

[Henrik Grunell, 2016/08/23 15:53:19]

I don't think an invalid value should be used to say it's unspecified. What
about making it a base::Optional?

[o1ka, 2016/08/23 16:20:56]

It would be a pain for IPC

[Henrik Grunell, 2016/08/24 12:47:15]

OK. It's still hacky I think to use the count to indicate unspecified. I'd
prefer an explicit "UNSPECIFIED" value. Let's see what the other reviewers say
about the general idea before digging in more.

   Reset(format, channel_layout, sample_rate, bits_per_sample,
         frames_per_buffer);
 }