Fix mac build for sync integration tests.
Fix mac build for sync integration tests.

The sync integration tests are missing some dependencies on mac, as a
result of which they crash when they are run. Adding this build flag
seems to fix the problem elsewhere in chrome_tests.gypi.

BUG=50789
TEST=sync_integration_tests

Review URL: http://codereview.chromium.org/3057030

git-svn-id: http://src.chromium.org/svn/trunk/src@54632 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 1c6d3934fee4549f7c0a1688b92523ce662aa9a7
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser