Fix log spam on 10.6 due to NSWindowFullScreenButton.

chrome/browser/ui/cocoa/browser_window_controller_private.mm

 // Copyright (c) 2012 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 "chrome/browser/ui/cocoa/browser_window_controller_private.h"
 
 #include <cmath>
 
 #include "base/command_line.h"
 #include "base/mac/bind_objc_block.h"
@@ skipping 824 matching lines @@
 
   [layout setInAnyFullscreen:[self isInAnyFullscreenMode]];
   [layout setFullscreenSlidingStyle:
       presentationModeController_.get().slidingStyle];
   [layout setFullscreenMenubarOffset:
       [presentationModeController_ menubarOffset]];
   [layout setFullscreenToolbarFraction:
       [presentationModeController_ toolbarFraction]];
 
   [layout setHasTabStrip:[self hasTabStrip]];
-  NSButton* fullScreenButton =
-      [[self window] standardWindowButton:NSWindowFullScreenButton];
+  // NSWindowFullScreenButton is 10.7+ and results in log spam on 10.6 if used.
+  NSButton* fullScreenButton = base::mac::IsOSSnowLeopard() ?
+      nil : [[self window] standardWindowButton:NSWindowFullScreenButton];
   [layout setFullscreenButtonFrame:fullScreenButton ? [fullScreenButton frame]
                                                     : NSZeroRect];
   if ([self shouldShowAvatar]) {
     NSView* avatar = [avatarButtonController_ view];
     [layout setShouldShowAvatar:YES];
     [layout setShouldUseNewAvatar:[self shouldUseNewAvatarButton]];
     [layout setAvatarSize:[avatar frame].size];
     [layout setAvatarLineWidth:[[avatar superview] cr_lineWidth]];
   }
 
@@ skipping 206 matching lines @@
 }
 
 - (BOOL)shouldConstrainFrameRect {
   if ([enterFullscreenTransition_ shouldWindowBeUnconstrained])
     return NO;
 
   return [super shouldConstrainFrameRect];
 }
 
 @end  // @implementation BrowserWindowController(Private)