tree 71e2f05521532466e2b262a40f97c552a4f6145a
parent 2dd351c3121f1257aed9b3a4bda70e32da5df913
author Peter Qiu <zqiu@chromium.org> 1399674449 -0700
committer chrome-internal-fetch <chrome-internal-fetch@google.com> 1400188163 +0000

Add metric for broken DNS configuration.

Attempt a DNS test using Google's public DNS server if portal detection
failed due to DNS failure, and report the result of the DNS test
to UMA metric.

BUG=chromium:366301
TEST=unit tests, manual
Manual Test:
1. Connect a chrome device to an AP with no internet access,
   then browse to "chrome://histograms" and verify there is a
   histogram for "Network.Shill.DNSTestResult" with a hit for
   value 1 (Failure).
2. Manually update the code to perform DNS test when portal detection
   succeed. Connect a chrome device to "GoogleGuest", and verify
   there is a hit for value 0 (Success) for the histogram
   "Network.Shill.DNSTestResult".

Change-Id: I8cb22f7664fcfa7fd08d3d3dd24902f7896a4e3e
Reviewed-on: https://chromium-review.googlesource.com/199174
Reviewed-by: Peter Qiu <zqiu@chromium.org>
Commit-Queue: Peter Qiu <zqiu@chromium.org>
Tested-by: Peter Qiu <zqiu@chromium.org>