Increase default buffer size when back end can't recommend one.

ppapi/shared_impl/ppb_audio_config_shared.cc

 // 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.
 
 #include "ppapi/shared_impl/ppb_audio_config_shared.h"
 #include "ppapi/thunk/enter.h"
 #include "ppapi/thunk/ppb_instance_api.h"
 
 namespace ppapi {
 
@@ skipping 56 matching lines @@
   if (hardware_sample_rate == sample_rate && hardware_sample_frame_count > 0) {
     // Round up input sample_frame_count to nearest multiple.
     uint32_t multiple = (sample_frame_count + hardware_sample_frame_count - 1) /
         hardware_sample_frame_count;
     uint32_t recommendation = hardware_sample_frame_count * multiple;
     if (recommendation > PP_AUDIOMAXSAMPLEFRAMECOUNT)
       recommendation = PP_AUDIOMAXSAMPLEFRAMECOUNT;
     return recommendation;
   }
 
-  // Otherwise, recommend a conservative 30ms buffer based on sample rate.
-  const uint32_t kDefault30msAt44100kHz = 1323;
-  const uint32_t kDefault30msAt48000kHz = 1440;
+  // Otherwise, recommend a conservative 50ms buffer based on sample rate.
+  const uint32_t kDefault50msAt44100kHz = 2205;
+  const uint32_t kDefault50msAt48000kHz = 2400;
   switch (sample_rate) {
     case PP_AUDIOSAMPLERATE_44100:
-      return kDefault30msAt44100kHz;
+      return kDefault50msAt44100kHz;
     case PP_AUDIOSAMPLERATE_48000:
-      return kDefault30msAt48000kHz;
+      return kDefault50msAt48000kHz;
     case PP_AUDIOSAMPLERATE_NONE:
       return 0;
   }
   // Unable to make a recommendation.
   return 0;
 }
 
 // static
 PP_AudioSampleRate PPB_AudioConfig_Shared::RecommendSampleRate(
     PP_Instance instance) {
@@ skipping 30 matching lines @@
   if (sample_frame_count > PP_AUDIOMAXSAMPLEFRAMECOUNT ||
       sample_frame_count < PP_AUDIOMINSAMPLEFRAMECOUNT)
     return false;
 
   sample_rate_ = sample_rate;
   sample_frame_count_ = sample_frame_count;
   return true;
 }
 
 }  // namespace ppapi