Enable PointerLockBrowserTestWithOptions.UnadjustedMovement

The tests in pointer_lock_browsertest.cc were flaky for 3 reasons:
- requestPointerLock being asynchronous
- mouse events being asynchronous
- native mouse events interfering with tests during execution
All the above were addressed in prior CLs.

Bug: 766450
Change-Id: Ic046bce6c81a9bcc8d1f78a5c56506ed959b45ec
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2213202Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Liviu Tinta <liviutinta@chromium.org>
Cr-Commit-Position: refs/heads/master@{#771844}

content/browser/pointer_lock_browsertest.cc

@@ -757,14 +757,7 @@ IN_PROC_BROWSER_TEST_F(PointerLockBrowserTestWithOptions,
 }
 
 #if defined(USE_AURA)
-#if defined(OS_WIN) || defined(OS_LINUX)
-// https://crbug.com/1043985#c9: Flaky on Windows and Linux.
-#define MAYBE_UnadjustedMovement DISABLED_UnadjustedMovement
-#else
-#define MAYBE_UnadjustedMovement UnadjustedMovement
-#endif
-IN_PROC_BROWSER_TEST_F(PointerLockBrowserTestWithOptions,
-                       MAYBE_UnadjustedMovement) {
+IN_PROC_BROWSER_TEST_F(PointerLockBrowserTestWithOptions, UnadjustedMovement) {
   GURL main_url(embedded_test_server()->GetURL(
       "a.com", "/cross_site_iframe_factory.html?a(b)"));
   EXPECT_TRUE(NavigateToURL(shell(), main_url));