Add method to create a ParcelSurfaceTexture from android.view.Surface.

Change-Id: I05e343ab7e327478f60322af9373574b70c148f5
diff --git a/include/surfaceflinger/Surface.h b/include/surfaceflinger/Surface.h
index 8845dc9..dc2a845 100644
--- a/include/surfaceflinger/Surface.h
+++ b/include/surfaceflinger/Surface.h
@@ -40,6 +40,7 @@
 class GraphicBuffer;
 class GraphicBufferMapper;
 class IOMX;
+class ISurfaceTexture;
 class Rect;
 class Surface;
 class SurfaceComposerClient;
@@ -154,6 +155,7 @@
     bool        isValid();
     uint32_t    getFlags() const    { return mFlags; }
     uint32_t    getIdentity() const { return mIdentity; }
+    sp<ISurfaceTexture> getSurfaceTexture();
 
     // the lock/unlock APIs must be used from the same thread
     status_t    lock(SurfaceInfo* info, bool blocking = true);