Bug 1188871: P2. Call DrainComplete should an error occurs while draining. r=snorp

Part 1 prevented draining when an error occurred first. This handles the case where an error occurs during draining.

dom/media/platforms/android/AndroidDecoderModule.cpp

@@ -393,6 +393,10 @@ nsresult MediaCodecDataDecoder::InitDecoder(Surface::Param aSurface)
 #define HANDLE_DECODER_ERROR() \
   if (NS_FAILED(res)) { \
     NS_WARNING("exiting decoder loop due to exception"); \
+    if (mDraining) { \
+      ENVOKE_CALLBACK(DrainComplete); \
+      mDraining = false; \
+    } \
     ENVOKE_CALLBACK(Error); \
     break; \
   }