Add getPointer for USAGE_SHARED allocations.

Change-Id: I13a2af09bbbeec6cc6131b935979ac21c02820be
diff --git a/rsAllocation.h b/rsAllocation.h
index b0f2f9e..b997f9a 100644
--- a/rsAllocation.h
+++ b/rsAllocation.h
@@ -163,6 +163,9 @@
     void ioSend(const Context *rsc);
     void ioReceive(const Context *rsc);
 
+    void * getPointer(const Context *rsc, uint32_t lod, RsAllocationCubemapFace face,
+                      uint32_t z, uint32_t array, size_t *stride);
+
 protected:
     Vector<const Program *> mToDirtyList;
     ObjectBaseRef<const Type> mType;