mac: Remove code that was only needed on 10.5

chrome/browser/ui/panels/panel_window_controller_cocoa.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.
 
 #include "chrome/browser/ui/panels/panel_window_controller_cocoa.h"
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/auto_reset.h"
 #include "base/logging.h"
@@ skipping 441 matching lines @@
 
 - (void)awakeFromNib {
   NSWindow* window = [self window];
 
   DCHECK(window);
   DCHECK(titlebar_view_);
   DCHECK_EQ(self, [window delegate]);
 
   [self updateWindowLevel];
 
-  if (base::mac::IsOSSnowLeopardOrLater()) {
-    [window setCollectionBehavior:
-        NSWindowCollectionBehaviorParticipatesInCycle];
-  }
+  [window setCollectionBehavior:NSWindowCollectionBehaviorParticipatesInCycle];
 
   [titlebar_view_ attach];
 
   // Set initial size of the window to match the size of the panel to give
   // the renderer the proper size to work with earlier, avoiding a resize
   // after the window is revealed.
   gfx::Rect panelBounds = windowShim_->panel()->GetBounds();
   NSRect frame = [window frame];
   frame.size.width = panelBounds.width();
   frame.size.height = panelBounds.height();
@@ skipping 559 matching lines @@
 - (NSRect)contentRectForFrameRect:(NSRect)frameRect {
   NSRect contentRect = [[[self window] contentView] convertRect:frameRect
                                                        fromView:nil];
   contentRect.size.height -= panel::kTitlebarHeight;
   if (contentRect.size.height < 0)
     contentRect.size.height = 0;
   return contentRect;
 }
 
 @end