[Mac] Avoid "adding unknown subview" warning.

chrome/browser/ui/cocoa/tabs/tab_window_controller.h

Index: chrome/browser/ui/cocoa/tabs/tab_window_controller.h
diff --git a/chrome/browser/ui/cocoa/tabs/tab_window_controller.h b/chrome/browser/ui/cocoa/tabs/tab_window_controller.h
index 407c794978e0bbb6adc82e0487dfe08bab1f8b2d..eb7519bf36857ceaf9611f23fedd7415128d4c40 100644
--- a/chrome/browser/ui/cocoa/tabs/tab_window_controller.h
+++ b/chrome/browser/ui/cocoa/tabs/tab_window_controller.h
@@ -18,6 +18,7 @@
 
 @class FastResizeView;
 @class FocusTracker;
+@class NSVisualEffectView;
 @class TabStripView;
 @class TabView;
 
@@ -26,6 +27,8 @@
   // Wrapper view around web content, and the developer tools view.
   base::scoped_nsobject<FastResizeView> tabContentArea_;
   base::scoped_nsobject<NSView> tabStripBackgroundView_;
+  // Used to blur the titlebar. nil if window does not have titlebar.

[tapted, 2016/10/11 04:21:43]

nit: blank line before

[Eugene But (OOO till 7-30), 2016/10/11 04:35:46]

Done.

+  base::scoped_nsobject<NSVisualEffectView> visualEffectView_;
 
   // The tab strip overlaps the titlebar of the window.
   base::scoped_nsobject<TabStripView> tabStripView_;