Headless: re-enable HeadlessBrowserContextIsolationTest

Bug: 930356
Change-Id: I1b1223bd6bbf11786090addf4e8f52135a5763d5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2451869
Auto-Submit: Andrey Kosyakov <caseq@chromium.org>
Reviewed-by: Peter Kvitek <kvitekp@chromium.org>
Commit-Queue: Peter Kvitek <kvitekp@chromium.org>
Commit-Queue: Andrey Kosyakov <caseq@chromium.org>
Cr-Commit-Position: refs/heads/master@{#814265}

headless/lib/headless_browser_context_browsertest.cc

@@ -151,8 +151,7 @@ class HeadlessBrowserContextIsolationTest
   std::unique_ptr<LoadObserver> load_observer_;
 };
 
-// TODO(https://crbug.com/930356): Re-enable test.
-DISABLED_HEADLESS_ASYNC_DEVTOOLED_TEST_F(HeadlessBrowserContextIsolationTest);
+HEADLESS_ASYNC_DEVTOOLED_TEST_F(HeadlessBrowserContextIsolationTest);
 
 class HeadlessBrowserUserDataDirTest : public HeadlessBrowserTest {
  protected: