Speculatively re-enable WebRequestAuthRequested test.

The SimpleURLLoader work mentioned in the bug seems to be done, and
the try jobs are passing. Enable it and see what happens?

Bug: 140976
Change-Id: Ic85aaa4352801fcc4be21a0d1dc7e1d4ed8df7c7
Reviewed-on: https://chromium-review.googlesource.com/c/1469293
Commit-Queue: David Benjamin <davidben@chromium.org>
Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#631992}

chrome/browser/extensions/api/web_request/web_request_apitest.cc

@@ -510,9 +510,7 @@ IN_PROC_BROWSER_TEST_F(ExtensionWebRequestApiTest,
       message_;
 }
 
-// Flaky (sometimes crash): http://crbug.com/140976
-IN_PROC_BROWSER_TEST_F(ExtensionWebRequestApiTest,
-                       DISABLED_WebRequestAuthRequired) {
+IN_PROC_BROWSER_TEST_F(ExtensionWebRequestApiTest, WebRequestAuthRequired) {
   CancelLoginDialog login_dialog_helper;
 
   ASSERT_TRUE(StartEmbeddedTestServer());