Revert "Update disabled ExtensionWebRequestApiTest"

This reverts commit 7b4f35d2.

Reason for revert: Test should be fixed now

Original change's description:
> Update disabled ExtensionWebRequestApiTest
> 
> TBR=grunell@chromium.org
> NOTRY=true
> 
> Bug: 859063
> Change-Id: Ie4248ed7493c81f946734678ddea9c228a8c0c24
> Reviewed-on: https://chromium-review.googlesource.com/1120160
> Reviewed-by: Yi Gu <yigu@chromium.org>
> Reviewed-by: Henrik Grunell <grunell@chromium.org>
> Commit-Queue: Yi Gu <yigu@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#571466}

TBR=grunell@chromium.org,yigu@chromium.org

Change-Id: I6ff7a455c9b06d5f0ef2a341a76d176e2d49ff84
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 859063
Reviewed-on: https://chromium-review.googlesource.com/1120467Reviewed-by: Ken Rockot <rockot@chromium.org>
Commit-Queue: Ken Rockot <rockot@chromium.org>
Cr-Commit-Position: refs/heads/master@{#571494}

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

@@ -694,13 +694,8 @@ IN_PROC_BROWSER_TEST_F(ExtensionWebRequestApiTest, IncognitoSplitModeReload) {
   EXPECT_TRUE(listener_incognito2.WaitUntilSatisfied());
 }
 
-// This test is flaky on Win7 debug build. See http://crbug.com/859063.
-#if defined(OS_WIN)
-#define MAYBE_ExtensionRequests DISABLED_ExtensionRequests
-#else
-#define MAYBE_ExtensionRequests ExtensionRequests
-#endif
-IN_PROC_BROWSER_TEST_F(ExtensionWebRequestApiTest, MAYBE_ExtensionRequests) {
+// This test is flaky. See http://crbug.com/859063.
+IN_PROC_BROWSER_TEST_F(ExtensionWebRequestApiTest, DISABLED_ExtensionRequests) {
   ASSERT_TRUE(StartEmbeddedTestServer());
   ExtensionTestMessageListener listener_main1("web_request_status1", true);
   ExtensionTestMessageListener listener_main2("web_request_status2", true);