Disable failing plugin tests on Win64

Look like we're trying to run 32-bit plugins for these,
which we don't support on Win64 yet.

BUG=180861
R=piman@chromium.org

Review URL: https://chromiumcodereview.appspot.com/12610005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@186769 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed