Exclude 32-bit specific files from Win64 build

R=gab@chromium.org, kerz@chromium.org
BUG=262193

Review URL: https://codereview.chromium.org/19616005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@212673 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed