Bug 3352047 Wrong message when adjusting volume

Add hidden AudioManager.getDevicesForStream and output device codes.

Change-Id: I4d1c1d3b6a077cd117720817d1f733dda557b947
diff --git a/media/libmedia/AudioSystem.cpp b/media/libmedia/AudioSystem.cpp
index 9d9b3c0..2f694ba 100644
--- a/media/libmedia/AudioSystem.cpp
+++ b/media/libmedia/AudioSystem.cpp
@@ -668,6 +668,13 @@
     return aps->getStrategyForStream(stream);
 }
 
+uint32_t AudioSystem::getDevicesForStream(AudioSystem::stream_type stream)
+{
+    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
+    if (aps == 0) return 0;
+    return aps->getDevicesForStream(stream);
+}
+
 audio_io_handle_t AudioSystem::getOutputForEffect(effect_descriptor_t *desc)
 {
     const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
diff --git a/media/libmedia/IAudioPolicyService.cpp b/media/libmedia/IAudioPolicyService.cpp
index 457f7ed..b89a278 100644
--- a/media/libmedia/IAudioPolicyService.cpp
+++ b/media/libmedia/IAudioPolicyService.cpp
@@ -49,7 +49,8 @@
     GET_OUTPUT_FOR_EFFECT,
     REGISTER_EFFECT,
     UNREGISTER_EFFECT,
-    IS_STREAM_ACTIVE
+    IS_STREAM_ACTIVE,
+    GET_DEVICES_FOR_STREAM,
 };
 
 class BpAudioPolicyService : public BpInterface<IAudioPolicyService>
@@ -263,6 +264,15 @@
         return reply.readInt32();
     }
 
+    virtual uint32_t getDevicesForStream(AudioSystem::stream_type stream)
+    {
+        Parcel data, reply;
+        data.writeInterfaceToken(IAudioPolicyService::getInterfaceDescriptor());
+        data.writeInt32(static_cast <uint32_t>(stream));
+        remote()->transact(GET_DEVICES_FOR_STREAM, data, &reply);
+        return (uint32_t) reply.readInt32();
+    }
+
     virtual audio_io_handle_t getOutputForEffect(effect_descriptor_t *desc)
     {
         Parcel data, reply;
@@ -495,6 +505,14 @@
             return NO_ERROR;
         } break;
 
+        case GET_DEVICES_FOR_STREAM: {
+            CHECK_INTERFACE(IAudioPolicyService, data, reply);
+            AudioSystem::stream_type stream =
+                    static_cast <AudioSystem::stream_type>(data.readInt32());
+            reply->writeInt32(static_cast <int>(getDevicesForStream(stream)));
+            return NO_ERROR;
+        } break;
+
         case GET_OUTPUT_FOR_EFFECT: {
             CHECK_INTERFACE(IAudioPolicyService, data, reply);
             effect_descriptor_t desc;