mac: Use NSWidth() and friends in a few more places.

ui/base/cocoa/base_view.mm

 // Copyright (c) 2011 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 "ui/base/cocoa/base_view.h"
 
 NSString* kViewDidBecomeFirstResponder =
     @"Chromium.kViewDidBecomeFirstResponder";
 NSString* kSelectionDirection = @"Chromium.kSelectionDirection";
 
@@ skipping 115 matching lines @@
 - (void)keyUp:(NSEvent*)theEvent {
   [self keyEvent:theEvent];
 }
 
 - (void)flagsChanged:(NSEvent*)theEvent {
   [self keyEvent:theEvent];
 }
 
 - (gfx::Rect)flipNSRectToRect:(NSRect)rect {
   gfx::Rect new_rect(NSRectToCGRect(rect));
-  new_rect.set_y([self bounds].size.height - new_rect.y() - new_rect.height());
+  new_rect.set_y(NSHeight([self bounds]) - new_rect.bottom());
   return new_rect;
 }
 
 - (NSRect)flipRectToNSRect:(gfx::Rect)rect {
   NSRect new_rect(NSRectFromCGRect(rect.ToCGRect()));
-  new_rect.origin.y =
-      [self bounds].size.height - new_rect.origin.y - new_rect.size.height;
+  new_rect.origin.y = NSHeight([self bounds]) - NSMaxY(new_rect);
   return new_rect;
 }
 
 @end