mac: Enable gn check for data vars pointing to directories below the build dir.

Mac bundles violate this constraint, so this adds many whitelist entries.
Fixing them seems not super easy, so I filed https://crbug.com/1000667 for it.

Bug: 1000667, 912946
Change-Id: Ibc1704fe779c6ccc86871a1b651f52572db3f919
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1780883
Commit-Queue: Nico Weber <thakis@chromium.org>
Reviewed-by: Takuto Ikuta <tikuta@chromium.org>
Auto-Submit: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#693705}

tools/mb/mb.py

@@ -1092,7 +1092,7 @@ class MetaBuildWrapper(object):
       # Skip a few configs that need extra cleanup for now.
       # TODO(https://crbug.com/912946): Fix everything on all platforms and
       # enable check everywhere.
-      if is_android or is_cros or is_mac:
+      if is_android or is_cros:
         break
 
       # Skip a few existing violations that need to be cleaned up. Each of
@@ -1103,7 +1103,19 @@ class MetaBuildWrapper(object):
           f == 'mr_extension/' or # https://crbug.com/997947
           f == 'locales/' or
           f.startswith('nacl_test_data/') or
-          f.startswith('ppapi_nacl_tests_libs/')):
+          f.startswith('ppapi_nacl_tests_libs/') or
+          (is_mac and f in (  # https://crbug.com/1000667
+              'Chromium Framework.framework/',
+              'Chromium Helper.app/',
+              'Chromium.app/',
+              'Content Shell.app/',
+              'blink_deprecated_test_plugin.plugin/',
+              'blink_test_plugin.plugin/',
+              'corb_test_plugin.plugin/',
+              'power_saver_test_plugin.plugin/',
+              'ppapi_tests.plugin/',
+              'ui_unittests Framework.framework/',
+          ))):
         continue
 
       # This runs before the build, so we can't use isdir(f). But