Widevine extractor changes to support secure media buffer playback.

Supports either secure or insecure buffer configurations, depending
on the build-time flag REQUIRE_SECURE_BUFFERS.

Change-Id: I5b8150315eced4ed9be656b73d91485a6216819d

proprietary/wvm/include/WVMMediaSource.h

@@ -43,6 +43,7 @@ public:
 
     virtual sp<MetaData> getFormat();
 
+    virtual status_t setBuffers(const Vector<MediaBuffer *> &buffers);
     virtual status_t read(MediaBuffer **buffer, const ReadOptions *options = NULL);
 
     static int sLastError;