GenericSource: gracefully handle missing timestamp

Bug: 23474771
Change-Id: I1a1c03162fb08fa43607905ff2c6d4d594675001
diff --git a/media/libmediaplayerservice/nuplayer/GenericSource.cpp b/media/libmediaplayerservice/nuplayer/GenericSource.cpp
index 08ac941..81aafbe 100644
--- a/media/libmediaplayerservice/nuplayer/GenericSource.cpp
+++ b/media/libmediaplayerservice/nuplayer/GenericSource.cpp
@@ -1428,7 +1428,11 @@
 
         if (err == OK) {
             int64_t timeUs;
-            CHECK(mbuf->meta_data()->findInt64(kKeyTime, &timeUs));
+            if (!mbuf->meta_data()->findInt64(kKeyTime, &timeUs)) {
+                mbuf->meta_data()->dumpToLog();
+                track->mPackets->signalEOS(ERROR_MALFORMED);
+                break;
+            }
             if (trackType == MEDIA_TRACK_TYPE_AUDIO) {
                 mAudioTimeUs = timeUs;
                 mBufferingMonitor->updateQueuedTime(true /* isAudio */, timeUs);