am 4719fa8a: libstagefright/matroska: Fix build with gcc 4.7

        }

        BlockIterator iter(this, info->mTrackNum);

        int32_t i = 0;

        int32_t j = 0;

        int64_t thumbnailTimeUs = 0;

        size_t maxBlockSize = 0;

        while (!iter.eos() && i < 20) {

        while (!iter.eos() && j < 20) {

            if (iter.block()->IsKey()) {

                ++i;

                ++j;

                size_t blockSize = 0;

                for (int i = 0; i < iter.block()->GetFrameCount(); ++i) {