Merge "Expose how many bytes are written in ProtoOutputStream"

    long long start(uint64_t fieldId);

    void end(long long token);

    /**

     * Returns how many bytes are buffered in ProtoOutputStream.

     * Notice, this is not the actual(compact) size of the output data.

     */

    size_t bytesWritten();

    /**

     * Flushes the protobuf data out to given fd. When the following functions are called,

     * it is not able to write to ProtoOutputStream any more since the data is compact.

    }

}

size_t

ProtoOutputStream::bytesWritten()

{

    return mBuffer.size();

}

bool

ProtoOutputStream::compact() {

    if (mCompact) return true;