Give time to free the port when shutting down apache on OSX.

Sometimes the next perf test would try to start the http server,
but the port wouldn't be available. This matches what we do on Linux.

In the long run, we should use a random port to avoid having to wait.

BUG=29228


Review URL: https://chromiumcodereview.appspot.com/10834299

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@151449 0039d316-1c4b-4281-b951-d872f2087c98

tools/python/google/platform_utils_mac.py

@@ -140,4 +140,6 @@ def GetStopHttpdCommand(self):
 
     if not self._httpd_cmd_string:
       return ["true"]   # Haven't been asked for the start cmd yet. Just pass.
-    return [self._bash, "-c", self._httpd_cmd_string + ' -k stop']
+    # Add a sleep after the shutdown because sometimes it takes some time for
+    # the port to be available again.
+    return [self._bash, "-c", self._httpd_cmd_string + ' -k stop && sleep 5']