GenericSource: support disconnect before NuCachedSource2 is created

Bug: 17672488
Change-Id: I96776c9679fdcfbe9a442c86447c59802b1465ac
diff --git a/media/libmediaplayerservice/nuplayer/GenericSource.h b/media/libmediaplayerservice/nuplayer/GenericSource.h
index 24bb6af..5ed4d52 100644
--- a/media/libmediaplayerservice/nuplayer/GenericSource.h
+++ b/media/libmediaplayerservice/nuplayer/GenericSource.h
@@ -126,6 +126,7 @@
 
     sp<DataSource> mDataSource;
     sp<NuCachedSource2> mCachedSource;
+    sp<DataSource> mHttpSource;
     sp<WVMExtractor> mWVMExtractor;
     sp<MetaData> mFileMeta;
     DrmManagerClient *mDrmManagerClient;