Re-enable ProxyBrowserTest.BasicAuthWSConnect

The browser test ProxyBrowserTest.BasicAuthWSConnect was flaky because
the testserver.py proxy it configured could only handle one request at a
time, and other parts of the browser randomly launched unrelated
requests while the test was running, occasionally taking the proxy's one
request until the test timed out.

testserver.py's basic auth proxy mode has been modified to support
multiple simultaneous requests, so the
ProxyBrowserTest.BasicAuthWSConnect test should no longer be
flaky. Re-enable it.

BUG=822614

Change-Id: Id390f01807b532316e3aa2d4de199e8082ae0bf0
Reviewed-on: https://chromium-review.googlesource.com/999374Reviewed-by: Matt Menke <mmenke@chromium.org>
Commit-Queue: Adam Rice <ricea@chromium.org>
Cr-Commit-Position: refs/heads/master@{#549497}

chrome/browser/net/proxy_browsertest.cc

@@ -110,9 +110,7 @@ class ProxyBrowserTest : public InProcessBrowserTest {
 };
 
 // We bypass manually installed proxy for localhost on chromeos.
-// TODO(crbug.com/822614): Flaky on Windows Debug and ASAN bots.
-#if (defined(OS_CHROMEOS) || defined(ADDRESS_SANITIZER) || \
-     defined(OS_WIN) || defined(OS_MACOSX))
+#if defined(OS_CHROMEOS)
 #define MAYBE_BasicAuthWSConnect DISABLED_BasicAuthWSConnect
 #else
 #define MAYBE_BasicAuthWSConnect BasicAuthWSConnect