Remove the simplified-fullscreen-ui flag on Mac.

chrome/browser/ui/exclusive_access/exclusive_access_manager.cc

 // Copyright (c) 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/exclusive_access/exclusive_access_manager.h"
 
 #include "base/command_line.h"
 #include "build/build_config.h"
 #include "chrome/browser/app_mode/app_mode_utils.h"
 #include "chrome/browser/ui/browser.h"
@@ skipping 90 matching lines @@
   return result;
 }
 
 // static
 bool ExclusiveAccessManager::IsExperimentalKeyboardLockUIEnabled() {
   return base::FeatureList::IsEnabled(features::kExperimentalKeyboardLockUI);
 }
 
 // static
 bool ExclusiveAccessManager::IsSimplifiedFullscreenUIEnabled() {
+#if defined(OS_MACOSX)
+  // Always enabled on Mac (the mouse cursor tracking required to implement the
+  // non-simplified version is not implemented).
+  return true;
+#else
   return base::FeatureList::IsEnabled(features::kSimplifiedFullscreenUI);
+#endif
 }
 
 void ExclusiveAccessManager::OnTabDeactivated(WebContents* web_contents) {
   fullscreen_controller_.OnTabDeactivated(web_contents);
   mouse_lock_controller_.OnTabDeactivated(web_contents);
 }
 
 void ExclusiveAccessManager::OnTabDetachedFromView(WebContents* web_contents) {
   fullscreen_controller_.OnTabDetachedFromView(web_contents);
   mouse_lock_controller_.OnTabDetachedFromView(web_contents);
@@ skipping 95 matching lines @@
   if (fullscreen)
     fullscreen_controller_.RecordBubbleReshownUMA();
   if (mouselock)
     mouse_lock_controller_.RecordBubbleReshownUMA();
 }
 
 void ExclusiveAccessManager::HandleUserHeldEscape() {
   fullscreen_controller_.HandleUserPressedEscape();
   mouse_lock_controller_.HandleUserPressedEscape();
 }