[Mac] Avoid "adding unknown subview" warning.

chrome/browser/ui/cocoa/framed_browser_window.h

Index: chrome/browser/ui/cocoa/framed_browser_window.h
diff --git a/chrome/browser/ui/cocoa/framed_browser_window.h b/chrome/browser/ui/cocoa/framed_browser_window.h
index d435422f009773eba4e4990122837b648454a123..cdeb6192e97cebcd46f64c9a4fc3c7a9558a5908 100644
--- a/chrome/browser/ui/cocoa/framed_browser_window.h
+++ b/chrome/browser/ui/cocoa/framed_browser_window.h
@@ -19,10 +19,6 @@ const NSInteger kFramedWindowButtonsWithTabStripOffsetFromLeft = 11;
 const NSInteger kFramedWindowButtonsWithoutTabStripOffsetFromTop = 4;
 const NSInteger kFramedWindowButtonsWithoutTabStripOffsetFromLeft = 8;
 
-// The amount of window background image that is painted at the top of the
-// window, so that it shows behind the tap strip area.
-const CGFloat kBrowserFrameViewPaintHeight = 60.0;
-
 // Cocoa class representing a framed browser window.
 // We need to override NSWindow with our own class since we need access to all
 // unhandled keyboard events and subclassing NSWindow is the only method to do
@@ -42,6 +38,10 @@ const CGFloat kBrowserFrameViewPaintHeight = 60.0;
   CGFloat windowButtonsInterButtonSpacing_;
 }
 
+// The amount of window background image that is painted at the top of the
+// window, so that it shows behind the tap strip area.
++ (CGFloat)browserFrameViewPaintHeight;
+
 // Designated initializer.
 - (id)initWithContentRect:(NSRect)contentRect
               hasTabStrip:(BOOL)hasTabStrip;