Revert "Disable flaky...

Revert "Disable flaky ContentSubresourceFilterThrottleManagerTest.ActivateMainFrameAndFilterSubframeNavigation"

This reverts commit c5ab8e6f.

Reason for revert: Root cause is unrelated to this test. See crbug.com/1011275

Original change's description:
> Disable flaky ContentSubresourceFilterThrottleManagerTest.ActivateMainFrameAndFilterSubframeNavigation
> 
> TBR=battre@chromium.org
> 
> Bug: 1010687
> Change-Id: I812d814b45c9ca6921f3d23bc2b11558e87d6472
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1836297
> Commit-Queue: Yoichi Osato <yoichio@chromium.org>
> Reviewed-by: Yoichi Osato <yoichio@chromium.org>
> Auto-Submit: Yoichi Osato <yoichio@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#702678}

TBR=battre@chromium.org,yoichio@chromium.org

Change-Id: Ia7fd5899cdc4ce42ff7a66a81b6fd69597db082d
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1010687
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1839952Reviewed-by: Dominic Battré <battre@chromium.org>
Commit-Queue: Dominic Battré <battre@chromium.org>
Cr-Commit-Position: refs/heads/master@{#702776}

components/subresource_filter/content/browser/content_subresource_filter_throttle_manager_unittest.cc

@@ -337,16 +337,8 @@ INSTANTIATE_TEST_SUITE_P(,
                          ::testing::Values(WILL_START_REQUEST,
                                            WILL_PROCESS_RESPONSE));
 
-// Flaky on Win and Linux. http://crbug.com/1010687
-#if defined(OS_LINUX) || defined(OS_WIN)
-#define MAYBE_ActivateMainFrameAndFilterSubframeNavigation \
-  DISABLED_ActivateMainFrameAndFilterSubframeNavigation
-#else
-#define MAYBE_ActivateMainFrameAndFilterSubframeNavigation \
-  ActivateMainFrameAndFilterSubframeNavigation
-#endif
 TEST_P(ContentSubresourceFilterThrottleManagerTest,
-       MAYBE_ActivateMainFrameAndFilterSubframeNavigation) {
+       ActivateMainFrameAndFilterSubframeNavigation) {
   // Commit a navigation that triggers page level activation.
   NavigateAndCommitMainFrame(GURL(kTestURLWithActivation));
   ExpectActivationSignalForFrame(main_rfh(), true /* expect_activation */);