disable ExtensionWebRequestApiAuthRequiredTest.WebRequestAuthRequired

Test is flaky on
https://ci.chromium.org/p/chromium/builders/try/linux_chromium_asan_rel_ng/381379

TBR=karandeepb@chromium.org
BUG=1003598
NOTRY=true

Change-Id: I2402407f109592cdea7bb0f70529fbd25da9d168
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1824790Reviewed-by: Takuto Ikuta <tikuta@chromium.org>
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Cr-Commit-Position: refs/heads/master@{#699677}

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

@@ -526,10 +526,9 @@ class ExtensionWebRequestApiAuthRequiredTest
   }
 };
 
-// Note: this is flaky on multiple platforms (crbug.com/1003598). Temporarily
-// enabled to find flakiness cause.
+// Note: this is flaky on multiple platforms (crbug.com/1003598).
 IN_PROC_BROWSER_TEST_P(ExtensionWebRequestApiAuthRequiredTest,
-                       WebRequestAuthRequired) {
+                       DISABLED_WebRequestAuthRequired) {
   CancelLoginDialog login_dialog_helper;
 
   ASSERT_TRUE(StartEmbeddedTestServer());