[ChromeDriver] Disable a test causing flakiness on Mac

Disable test case ChromeDriverSiteIsolation.testCanClickOOPIF on Mac.
It appears to occasionally put the test HTTP server into a bad state,
causing large number of failures in subsequent test cases.

TBR=crouleau@chromium.org

Bug: 904061
Change-Id: I230b445dd701a1c894fb65a51a60933ab586bc23
Reviewed-on: https://chromium-review.googlesource.com/c/1335271Reviewed-by: John Chen <johnchen@chromium.org>
Commit-Queue: John Chen <johnchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607905}

chrome/test/chromedriver/test/run_py_tests.py

@@ -183,6 +183,12 @@ _INTEGRATION_NEGATIVE_FILTER = [
     'SessionHandlingTest.testGetSessions',
 ]
 
+# https://crbug.com/904061
+if util.GetPlatformName() == 'mac':
+  _INTEGRATION_NEGATIVE_FILTER += [
+    'ChromeDriverSiteIsolation.testCanClickOOPIF',
+  ]
+
 
 def _GetDesktopNegativeFilter(version_name):
   filter = _NEGATIVE_FILTER + _DESKTOP_NEGATIVE_FILTER