[Mac] Adds a flag to force 10.6-style fullscreen for testing.

chrome/browser/ui/cocoa/panels/display_settings_provider_cocoa.mm

Index: chrome/browser/ui/cocoa/panels/display_settings_provider_cocoa.mm
diff --git a/chrome/browser/ui/cocoa/panels/display_settings_provider_cocoa.mm b/chrome/browser/ui/cocoa/panels/display_settings_provider_cocoa.mm
index 7c704f7e62336a38b7ba6fb22d76a82e68d476f6..098580f7708b105c12946d2c641f1f6fb87efbc1 100644
--- a/chrome/browser/ui/cocoa/panels/display_settings_provider_cocoa.mm
+++ b/chrome/browser/ui/cocoa/panels/display_settings_provider_cocoa.mm
@@ -7,6 +7,7 @@
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop.h"
 #include "chrome/browser/chrome_notification_types.h"
+#include "chrome/browser/fullscreen.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/cocoa/last_active_browser_cocoa.h"
@@ -93,13 +94,13 @@ bool DisplaySettingsProviderCocoa::NeedsPeriodicFullScreenCheck() const {
   // So we don't need to do anything when any other application enters
   // fullscreen mode. We still need to handle the case when chrome enters
   // fullscreen mode and our topmost windows will not get hided by the system.
-  return !base::mac::IsOSLionOrLater();
+  return !chrome::mac::SupportsSystemFullscreen();
 }
 
 bool DisplaySettingsProviderCocoa::IsFullScreen() {
   // For Lion and later, we only need to check if chrome enters fullscreen mode
   // (see detailed reason above in NeedsPeriodicFullScreenCheck).
-  if (!base::mac::IsOSLionOrLater())
+  if (!chrome::mac::SupportsSystemFullscreen())
     return DisplaySettingsProvider::IsFullScreen();
 
   Browser* browser = chrome::GetLastActiveBrowser();