Add MODIFY_AUDIO_SETTINGS permission in Android manifest and implementation in audio manager.

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/logging.h"
+#include "jni/AudioManagerAndroid_jni.h"
 #include "media/audio/android/opensles_input.h"
 #include "media/audio/android/opensles_output.h"
 #include "media/audio/audio_manager.h"
 #include "media/audio/audio_parameters.h"
 #include "media/audio/audio_util.h"
 #include "media/audio/fake_audio_input_stream.h"
 #include "media/base/channel_layout.h"
 
 namespace media {
 
@@ skipping 35 matching lines @@
   static const int kDefaultSampleRate = 16000;
   static const int kDefaultBufferSize = 1024;
   return AudioParameters(
       AudioParameters::AUDIO_PCM_LOW_LATENCY, CHANNEL_LAYOUT_STEREO,
       kDefaultSampleRate, 16, kDefaultBufferSize);
 }
 
 AudioOutputStream* AudioManagerAndroid::MakeLinearOutputStream(
       const AudioParameters& params) {
   DCHECK_EQ(AudioParameters::AUDIO_PCM_LINEAR, params.format());
+  SetAudioMode(kAudioModeNormal);

[no longer working on chromium, 2013/03/11 16:07:54]

could you please explain why MakeLinearOutputStream and
MakeLowLatencyOutputStream are using different modes?

   return new OpenSLESOutputStream(this, params);
 }
 
 AudioOutputStream* AudioManagerAndroid::MakeLowLatencyOutputStream(
       const AudioParameters& params) {
   DCHECK_EQ(AudioParameters::AUDIO_PCM_LOW_LATENCY, params.format());
+  SetAudioMode(kAudioModeInCommunication);
   return new OpenSLESOutputStream(this, params);
 }
 
 AudioInputStream* AudioManagerAndroid::MakeLinearInputStream(
     const AudioParameters& params, const std::string& device_id) {
   DCHECK_EQ(AudioParameters::AUDIO_PCM_LINEAR, params.format());
   return new OpenSLESInputStream(this, params);
 }
 
 AudioInputStream* AudioManagerAndroid::MakeLowLatencyInputStream(
     const AudioParameters& params, const std::string& device_id) {
   DCHECK_EQ(AudioParameters::AUDIO_PCM_LOW_LATENCY, params.format());
   return new OpenSLESInputStream(this, params);
 }
 
+// static
+bool AudioManagerAndroid::RegisterAudioManager(JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
+
 AudioParameters AudioManagerAndroid::GetPreferredOutputStreamParameters(
     const AudioParameters& input_params) {
   // TODO(xians): figure out the right output sample rate and sample rate to
   // achieve the best audio performance for Android devices.
   static const int kDefaultSampleRate = 16000;
   static const int kDefaultBufferSize = 1024;
 
   ChannelLayout channel_layout = CHANNEL_LAYOUT_STEREO;
   int sample_rate = kDefaultSampleRate;
   int buffer_size = kDefaultBufferSize;
@@ skipping 15 matching lines @@
 
   int user_buffer_size = GetUserBufferSize();
   if (user_buffer_size)
     buffer_size = user_buffer_size;
 
   return AudioParameters(
       AudioParameters::AUDIO_PCM_LOW_LATENCY, channel_layout, input_channels,
       sample_rate, bits_per_sample, buffer_size);
 }
 
+void AudioManagerAndroid::SetAudioMode(int mode) {
+  JNIEnv* env = base::android::AttachCurrentThread();
+  DCHECK(env);
+  jobject context = base::android::GetApplicationContext();
+  DCHECK(context);
+
+  Java_AudioManagerAndroid_setMode(env, context, mode);
+}
+
 }  // namespace media