Change to interface to M19, add a few more test cases to test_audio.

ppapi/api/ppb_audio_config.idl

 /* Copyright (c) 2012 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 /**
  * This file defines the PPB_AudioConfig interface for establishing an
  * audio configuration resource within the browser.
  */
 
 label Chrome {
   M14 = 1.0,
-  M18 = 1.1
+  M19 = 1.1
 };
 
 /**
  * This enumeration contains audio frame count constants.
  * <code>PP_AUDIOMINSAMPLEFRAMECOUNT</code> is the minimum possible frame
  * count. <code>PP_AUDIOMAXSAMPLEFRAMECOUNT</code> is the maximum possible
  * frame count.
  */
 [unnamed] enum PP_AudioFrameSize {
   PP_AUDIOMINSAMPLEFRAMECOUNT = 64,
@@ skipping 103 matching lines @@
    * closest to the requested count. The sample frame count determines the
    * overall latency of audio. Since one "frame" is always buffered in advance,
    * smaller frame counts will yield lower latency, but higher CPU utilization.
    *
    * Supported sample frame counts will vary by hardware and system (consider
    * that the local system might be anywhere from a cell phone or a high-end
    * audio workstation). Sample counts less than
    * <code>PP_AUDIOMINSAMPLEFRAMECOUNT</code> and greater than
    * <code>PP_AUDIOMAXSAMPLEFRAMECOUNT</code> are never supported on any
    * system, but values in between aren't necessarily valid. This function
-   * will return a supported count closest to the requested value.
+   * will return a supported count closest to the requested frame count.
    *
    * RecommendSampleFrameCount() result is intended for audio output devices.
    *
    * @param[in] instance
    * @param[in] sample_rate A <code>PP_AudioSampleRate</code> which is either
    * <code>PP_AUDIOSAMPLERATE_44100</code> or
    * <code>PP_AUDIOSAMPLERATE_48000.</code>
    * @param[in] requested_sample_frame_count A <code>uint_32t</code> requested
    * frame count.
    *
@@ skipping 44 matching lines @@
    * 0 if the resource is invalid. Refer to
    * RecommendSampleFrameCount() for more on sample frame counts.
    */
   uint32_t GetSampleFrameCount(
       [in] PP_Resource config);
 
   /**
    * RecommendSampleRate() returns the native sample rate that the browser
    * is using in the backend.  Applications that use the recommended sample
    * rate will have potentially better latency and fidelity.  The return value
-   * is indended for audio output devices.
+   * is indended for audio output devices.  If the output sample rate cannot be
+   * determined, this function can return PP_AUDIOSAMPLERATE_NONE.
    *
    * @param[in] instance
    *
    * @return A <code>uint32_t</code> containing the recommended sample frame
    * count if successful.
    */
   [version=1.1]
   PP_AudioSampleRate RecommendSampleRate(
       [in] PP_Instance instance);
 
 };