update offloaded audio track sampling rate

AudioPlayer must read the sampling rate from offloaded audio sinks
whenever a new time position is computed as the decoder can update
the sampling rate on the fly.

Change-Id: I997e5248cfd4017aeceb4e11689324ded2a5bc88
diff --git a/media/libmediaplayerservice/MediaPlayerService.cpp b/media/libmediaplayerservice/MediaPlayerService.cpp
index cd052e6..9ac9105 100644
--- a/media/libmediaplayerservice/MediaPlayerService.cpp
+++ b/media/libmediaplayerservice/MediaPlayerService.cpp
@@ -1813,6 +1813,12 @@
     return mSessionId;
 }
 
+uint32_t MediaPlayerService::AudioOutput::getSampleRate() const
+{
+    if (mTrack == 0) return 0;
+    return mTrack->getSampleRate();
+}
+
 #undef LOG_TAG
 #define LOG_TAG "AudioCache"
 MediaPlayerService::AudioCache::AudioCache(const sp<IMemoryHeap>& heap) :
@@ -2015,6 +2021,14 @@
     return 0;
 }
 
+uint32_t MediaPlayerService::AudioCache::getSampleRate() const
+{
+    if (mMsecsPerFrame == 0) {
+        return 0;
+    }
+    return (uint32_t)(1.e3 / mMsecsPerFrame);
+}
+
 void MediaPlayerService::addBatteryData(uint32_t params)
 {
     Mutex::Autolock lock(mLock);