Consolidate SDK forwards in sdk_forward_declarations.h.

ui/message_center/cocoa/popup_controller.mm

 // Copyright (c) 2013 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.
 
 #import "ui/message_center/cocoa/popup_controller.h"
 
 #include <cmath>
 
 #import "base/mac/foundation_util.h"
 #import "base/mac/sdk_forward_declarations.h"
 #import "ui/base/cocoa/window_size_constants.h"
 #import "ui/message_center/cocoa/notification_controller.h"
 #import "ui/message_center/cocoa/popup_collection.h"
 #include "ui/message_center/message_center.h"
 
-#if !defined(MAC_OS_X_VERSION_10_7) || \
-    MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_7
-enum {
-  NSWindowCollectionBehaviorFullScreenAuxiliary = 1 << 8
-};
-#endif  // MAC_OS_X_VERSION_10_7
-
 ////////////////////////////////////////////////////////////////////////////////
 
 @interface MCPopupController (Private)
 - (void)notificationSwipeStarted;
 - (void)notificationSwipeMoved:(CGFloat)amount;
 - (void)notificationSwipeEnded:(BOOL)ended complete:(BOOL)isComplete;
 @end
 
 // Window Subclass /////////////////////////////////////////////////////////////
 
@@ skipping 240 matching lines @@
 
 - (void)mouseEntered:(NSEvent*)event {
   messageCenter_->PausePopupTimers();
 }
 
 - (void)mouseExited:(NSEvent*)event {
   messageCenter_->RestartPopupTimers();
 }
 
 @end