Expand the workaround in r149575 to cover more builders.

This applies the mmap workaround to all "Chrome" builds, since we're
also seeing the error on Chrome continuous branch builders, which aren't
marked as "Official" builds.

Review URL: https://chromiumcodereview.appspot.com/10823264

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@150905 0039d316-1c4b-4281-b951-d872f2087c98

chrome/chrome_tests.gypi

@@ -2283,7 +2283,7 @@
             '../ui/aura/aura.gyp:test_support_aura',
           ],
         }],
-        ['OS=="linux" and buildtype=="Official" and target_arch=="ia32"', {
+        ['OS=="linux" and branding=="Chrome" and target_arch=="ia32"', {
           'configurations': {
             'Release': {
               'ldflags': [