Add a way to retrieve a Region as a SharedBuffer

Change-Id: Ia53cb905fbc88f899521658545f990fb9217b1e1

include/utils/SharedBuffer.h

@@ -96,7 +96,7 @@ private:
         inline ~SharedBuffer() { }
         inline SharedBuffer(const SharedBuffer&);
  
-        // 16 bytes. must be sized to preserve correct alingment.
+        // 16 bytes. must be sized to preserve correct alignment.
         mutable int32_t        mRefs;
                 size_t         mSize;
                 uint32_t       mReserved[2];