Fix build with system yasm.

BUG=100078
Review URL: http://codereview.chromium.org/8243012

Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 371e1091ebd6af7f6e110a84fd105f6c81a1fb88
1 file changed
tree: 572e5adafb95646902cc6c2b385793a989bcef58
  1. README.chromium
  2. source/
  3. yasm.gyp
  4. yasm_compile.gypi