Fix the choppiness for the pulse impl when using a smaller buffer size like 512 samples

media/audio/pulse/pulse_output.cc

Index: media/audio/pulse/pulse_output.cc
diff --git a/media/audio/pulse/pulse_output.cc b/media/audio/pulse/pulse_output.cc
index 7cf66cb10c801ba9f7de12c9aae90d1e7e06dc40..ca8fb7f7e2514d51420b3494154abd0a7752d740 100644
--- a/media/audio/pulse/pulse_output.cc
+++ b/media/audio/pulse/pulse_output.cc
@@ -288,6 +288,14 @@ void PulseAudioOutputStream::FulfillWriteRequest(size_t requested_bytes) {
     bytes_remaining -= bytes_to_fill;
     current_frame = frames_to_fill;
   }
+
+  size_t avialable_space = pa_stream_writable_size(pa_stream_);

[DaleCurtis, 2013/02/25 19:01:29]

s/avialable_space/available_space/

[no longer working on chromium, 2013/02/25 20:03:19]

Sorry, I will change it to writable_space

+  if (avialable_space >= static_cast<size_t>(params_.GetBytesPerBuffer())) {
+    if (source_callback_)
+      source_callback_->WaitTillDataReady();
+
+    FulfillWriteRequest(params_.GetBytesPerBuffer());

[DaleCurtis, 2013/02/25 19:01:29]

Hmm, won't this cause faster than normal playback?  Can you try this with some
flash and html5 videos?

[no longer working on chromium, 2013/02/25 20:03:19]

It should not cause fast playback, since we query the pulse server on the
writable space and write data to the driver, and the pulse is still playing
sound in its normal speed.

I have already tried some html5 sounds, webrtc and webaudio, they all sound
great (and much better for webrtc), and will do some more tests on flash
tomorrow.

+  }
 }
 
 void PulseAudioOutputStream::Start(AudioSourceCallback* callback) {