Revert 171681

media/audio/mac/audio_input_mac.cc

Index: media/audio/mac/audio_input_mac.cc
===================================================================
--- media/audio/mac/audio_input_mac.cc	(revision 171691)
+++ media/audio/mac/audio_input_mac.cc	(working copy)
@@ -192,31 +192,12 @@
     return;
   }
 
-  if (audio_buffer->mAudioDataByteSize) {
-    // The AudioQueue API may use a large internal buffer and repeatedly call us
-    // back to back once that internal buffer is filled.  When this happens the
-    // renderer client does not have enough time to read data back from the
-    // shared memory before the next write comes along.  If HandleInputBuffer()
-    // is called too frequently, Sleep() to simulate realtime input and ensure
-    // the shared memory doesn't get trampled.
-    // TODO(dalecurtis): This is a HACK.  Long term the AudioQueue path is going
-    // away in favor of the AudioUnit based AUAudioInputStream().  Tracked by
-    // http://crbug.com/161383
-    base::TimeDelta elapsed = base::Time::Now() - last_fill_;
-    base::TimeDelta buffer_length = base::TimeDelta::FromMilliseconds(
-       audio_buffer->mAudioDataByteSize * base::Time::kMillisecondsPerSecond /
-       static_cast<float>(format_.mBytesPerFrame * format_.mSampleRate));
-    if (elapsed < buffer_length)
-      base::PlatformThread::Sleep(buffer_length - elapsed);
-
+  if (audio_buffer->mAudioDataByteSize)
     callback_->OnData(this,
                       reinterpret_cast<const uint8*>(audio_buffer->mAudioData),
                       audio_buffer->mAudioDataByteSize,
                       audio_buffer->mAudioDataByteSize,
                       0.0);
-
-    last_fill_ = base::Time::Now();
-  }
   // Recycle the buffer.
   OSStatus err = QueueNextBuffer(audio_buffer);
   if (err != noErr) {