Try x64 binary for symupload

symupload is still failing for chrome_child.dll on the 32 bit official
bots. One last try of making an x64 binary instead, and then I'm going
to give up.

TBR=mark@chromium.org
BUG=678874, 696257, 696671, 696911,697638

Review-Url: https://codereview.chromium.org/2723233003
Cr-Original-Commit-Position: refs/heads/master@{#454089}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 73dd82d9969add23c5070c12cdbeba8e9e3f13ff
1 file changed