Fix a bug in the minidump symbolizer.
Fix a bug in the minidump symbolizer.

TBR=chrisha@chromium.org

BUG=

Review URL: https://codereview.appspot.com/216300043

wangming28/syzygy,Eloston/syzygy,supriyantomaftuh/syzygy,google/syzygy,supriyantomaftuh/syzygy,wangming28/syzygy,supriyantomaftuh/syzygy,supriyantomaftuh/syzygy,google/syzygy,wangming28/syzygy,google/syzygy,google/syzygy,wangming28/syzygy,Eloston/syzygy