AudioFlinger: Offload track transition fix

Trigger state changes in OffloadThread on adding a new offload track.

Bug: 12530661
Change-Id: I95b62764c7ac041d470702e86b951f812eb0e70f
diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index cecb3dc..7de688e 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -1490,9 +1490,7 @@
         status = NO_ERROR;
     }
 
-    ALOGV("signal playback thread");
-    broadcast_l();
-
+    onAddNewTrack_l();
     return status;
 }
 
@@ -2758,6 +2756,12 @@
     }
 }
 
+void AudioFlinger::PlaybackThread::onAddNewTrack_l()
+{
+    ALOGV("signal playback thread");
+    broadcast_l();
+}
+
 void AudioFlinger::MixerThread::threadLoop_mix()
 {
     // obtain the presentation timestamp of the next output buffer
@@ -4080,7 +4084,6 @@
                         // seek when resuming.
                         if (previousTrack->sessionId() != track->sessionId()) {
                             previousTrack->invalidate();
-                            mFlushPending = true;
                         }
                     }
                 }
@@ -4223,6 +4226,18 @@
     }
 }
 
+void AudioFlinger::OffloadThread::onAddNewTrack_l()
+{
+    sp<Track> previousTrack = mPreviousTrack.promote();
+    sp<Track> latestTrack = mLatestActiveTrack.promote();
+
+    if (previousTrack != 0 && latestTrack != 0 &&
+        (previousTrack->sessionId() != latestTrack->sessionId())) {
+        mFlushPending = true;
+    }
+    PlaybackThread::onAddNewTrack_l();
+}
+
 // ----------------------------------------------------------------------------
 
 AudioFlinger::DuplicatingThread::DuplicatingThread(const sp<AudioFlinger>& audioFlinger,