Add detection for repeated audio in capturing.

content/renderer/media/media_stream_audio_processor_unittest.cc

Index: content/renderer/media/media_stream_audio_processor_unittest.cc
diff --git a/content/renderer/media/media_stream_audio_processor_unittest.cc b/content/renderer/media/media_stream_audio_processor_unittest.cc
index 20eb181240206123bcaa6e75fb764533747dd93d..a00a500afed2f18d3c15df84ebff4bfe3af36780 100644
--- a/content/renderer/media/media_stream_audio_processor_unittest.cc
+++ b/content/renderer/media/media_stream_audio_processor_unittest.cc
@@ -456,7 +456,7 @@ TEST_F(MediaStreamAudioProcessorTest, MAYBE_TestAllSampleRates) {
   EXPECT_TRUE(audio_processor->has_audio_processing());
 
   static const int kSupportedSampleRates[] =
-      { 8000, 16000, 22050, 32000, 44100, 48000, 88200, 96000 };
+      { 8000, 16000, 32000, 44100, 48000, 88200, 96000 };

[tommi (sloooow) - chröme, 2015/09/25 08:57:14]

why this change? (I didn't see anything in the description that 22050 wasn't
supported)

[minyue, 2015/09/25 14:40:06]

The problem is 10 ms @ 22050 Hz is 220.5 samples. I don't know how that is
handled. I had an offline discussion with Henrik and we thought that it would be
good to remove this rate in this test.

[tommi (sloooow) - chröme, 2015/09/25 14:56:58]

Hmm... from that answer it sounds like it's a corner case and we don't know how
our code handles it and therefore there's even more reason for it to be in
there... or?

what sort of problems did you run into?

[Henrik Grunell, 2015/09/27 07:34:11]

According to Henrik A, Chrome doesn't support 22050 for input, hence I thought
it's no point for the MSAP to support that. If this isn't correct we need to
look over the support for that since the test failed.

I don'd see any sample rate value sanity checks in MSAP, seems to swallow
anything > 0. Maybe supported rates should be explicit there.

[minyue, 2015/09/28 05:22:00]

22050 has been added back

   for (size_t i = 0; i < arraysize(kSupportedSampleRates); ++i) {
     int buffer_size = (kSupportedSampleRates[i] / 100)  < 128 ?
         kSupportedSampleRates[i] / 100 : 128;