[Mac] Fix isolated content_shell_crash_test.

The script pointed to the un-bundled Content Shell Framework, which is
not in the isolated inputs, rather than the Framework bundled in
Content Shell.app.

Bug: 850735
Change-Id: I873a94a0e1c6882704199d918d9f463d4a82a39b
Reviewed-on: https://chromium-review.googlesource.com/1099276Reviewed-by: Nico Weber <thakis@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#566982}

testing/scripts/content_shell_crash_test.py

@@ -57,7 +57,8 @@ def main(argv):
     # symbols are dumped for the Framework too.
     additional_args = [
         '--additional-binary',
-        os.path.join('Content Shell Framework.framework', 'Versions',
+        os.path.join('.', 'Content Shell.app', 'Contents', 'Frameworks',
+                     'Content Shell Framework.framework', 'Versions',
                      'Current', 'Content Shell Framework')
     ]
   else: