39     size_t bytesWritten() const { return fUsed; }  in bytesWritten()
50         fUsed = 0;
63         size_t offset = fUsed;  in reserve()
64         size_t totalRequired = fUsed + size;  in reserve()
68         fUsed = totalRequired;  in reserve()
79         SkASSERT(offset < fUsed);  in readTAt()
90         SkASSERT(offset < fUsed);  in overwriteTAt()
216         fUsed = offset;  in rewindToOffset()
221         memcpy(dst, fData, fUsed);  in flatten()
225         return stream->write(fData, fUsed);  in writeToStream()
243     size_t fUsed;                      // Number of bytes written.  variable