Enable high latency audio on Android N+ for basic playback.

media/audio/android/audio_manager_android.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 "media/audio/android/audio_manager_android.h"
 
 #include "base/android/build_info.h"
 #include "base/android/context_utils.h"
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
@@ skipping 314 matching lines @@
 
     // Pre-Lollipop devices don't support > stereo OpenSLES output and the
     // AudioManager APIs for GetOptimalOutputFrameSize() don't support channel
     // layouts greater than stereo unless low latency audio is supported.
     if (input_params.channels() <= 2 ||
         (base::android::BuildInfo::GetInstance()->sdk_int() >= 21 &&
          IsAudioLowLatencySupported())) {
       channel_layout = input_params.channel_layout();
     }
 
-    buffer_size = GetOptimalOutputFrameSize(
-        sample_rate, ChannelLayoutToChannelCount(channel_layout));
+    // For high latency playback, pass through the requested buffer size.
+    if (input_params.latency_tag() == AudioLatency::LATENCY_PLAYBACK) {
+      buffer_size = input_params.frames_per_buffer();
+    } else {
+      buffer_size = GetOptimalOutputFrameSize(
+          sample_rate, ChannelLayoutToChannelCount(channel_layout));
+    }
   }
 
   int user_buffer_size = GetUserBufferSize();
   if (user_buffer_size)
     buffer_size = user_buffer_size;
 
   return AudioParameters(AudioParameters::AUDIO_PCM_LOW_LATENCY, channel_layout,
                          sample_rate, bits_per_sample, buffer_size);
 }
 
@@ skipping 77 matching lines @@
   output_volume_override_ = volume;
 
   DCHECK(GetTaskRunner()->BelongsToCurrentThread());
   for (OutputStreams::iterator it = streams_.begin();
        it != streams_.end(); ++it) {
     (*it)->SetVolume(volume);
   }
 }
 
 }  // namespace media