Revert "Enable WebNavigationApiTest.ServerRedirect"

This reverts commit 6620ff85.

Reason for revert: flaky on Mac (https://build.chromium.org/p/chromium.mac/builders/Mac10.12%20Tests/builds/3516)



Original change's description:
> Enable WebNavigationApiTest.ServerRedirect
> 
> This test passes with iteration count of 100 locally. It should not be
> flaky, but let's try and see.
> 
> Bug: 660288
> Change-Id: I8f190be7f6b6639e048ea59f040ca0421c3b51bd
> Reviewed-on: https://chromium-review.googlesource.com/600492
> Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
> Commit-Queue: Nasko Oskov <nasko@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#491805}

TBR=nasko@chromium.org,alexmos@chromium.org

Change-Id: If1d0082640f0b69c193792dc108045f8cc7dd41d
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 660288
Reviewed-on: https://chromium-review.googlesource.com/602307Reviewed-by: Vasilii Sukhanov <vasilii@chromium.org>
Commit-Queue: Vasilii Sukhanov <vasilii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#492006}

chrome/browser/extensions/api/web_navigation/web_navigation_apitest.cc

@@ -399,7 +399,8 @@ IN_PROC_BROWSER_TEST_F(WebNavigationApiTest, ClientRedirect) {
       << message_;
 }
 
-IN_PROC_BROWSER_TEST_F(WebNavigationApiTest, ServerRedirect) {
+// http://crbug.com/660288
+IN_PROC_BROWSER_TEST_F(WebNavigationApiTest, DISABLED_ServerRedirect) {
   ASSERT_TRUE(StartEmbeddedTestServer());
   ASSERT_TRUE(RunExtensionTest("webnavigation/serverRedirect"))
       << message_;