[Mac] Give FullscreenControllerTest a ScopedFakeNSWindowFullscreen.

This may resolve crashes seen in the WindowServer on swarming.

Tbr: miu@chromium.org
Bug: 828031
Change-Id: Iadbb4bcd74b03ab6abe75efc9b1f02a704ca3b74
Reviewed-on: https://chromium-review.googlesource.com/992453
Commit-Queue: Robert Sesek <rsesek@chromium.org>
Reviewed-by: Erik Chen <erikchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#547803}

chrome/browser/ui/exclusive_access/fullscreen_controller_test.h

@@ -7,6 +7,7 @@
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
+#include "build/build_config.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/ui/exclusive_access/exclusive_access_bubble_hide_callback.h"
 #include "chrome/browser/ui/exclusive_access/exclusive_access_bubble_type.h"
@@ -15,6 +16,10 @@
 #include "content/public/browser/notification_service.h"
 #include "content/public/test/test_utils.h"
 
+#if defined(OS_MACOSX)
+#include "ui/base/test/scoped_fake_nswindow_fullscreen.h"
+#endif
+
 // Observer for NOTIFICATION_FULLSCREEN_CHANGED notifications.
 class FullscreenNotificationObserver
     : public content::WindowedNotificationObserver {
@@ -75,6 +80,13 @@ class FullscreenControllerTest : public InProcessBrowserTest {
   void ToggleTabFullscreen_Internal(bool enter_fullscreen,
                                     bool retry_until_success);
 
+#if defined(OS_MACOSX)
+  // On Mac, entering into the system fullscreen mode can tickle crashes in
+  // the WindowServer (c.f. https://crbug.com/828031), so provide a fake for
+  // testing.
+  ui::test::ScopedFakeNSWindowFullscreen fake_fullscreen_window_;
+#endif
+
   base::WeakPtrFactory<FullscreenControllerTest> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(FullscreenControllerTest);