Add ConsumerBase::isAbandoned

Bug: 20105644
Change-Id: I21526b5397ea51a15500c44a99daa9d75fc4ea67
diff --git a/libs/gui/ConsumerBase.cpp b/libs/gui/ConsumerBase.cpp
index 072ab44..0e42daf 100644
--- a/libs/gui/ConsumerBase.cpp
+++ b/libs/gui/ConsumerBase.cpp
@@ -171,6 +171,11 @@
     mConsumer.clear();
 }
 
+bool ConsumerBase::isAbandoned() {
+    Mutex::Autolock _l(mMutex);
+    return mAbandoned;
+}
+
 void ConsumerBase::setFrameAvailableListener(
         const wp<FrameAvailableListener>& listener) {
     CB_LOGV("setFrameAvailableListener");