Fix window zoom in a sane way, remove nasty casts.

chrome/browser/tab_contents/tab_contents_view_mac.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 <Carbon/Carbon.h>
 
 #include "chrome/browser/tab_contents/tab_contents_view_mac.h"
 
 #include <string>
 
@@ skipping 51 matching lines @@
 @end
 
 namespace tab_contents_view_mac {
 TabContentsView* CreateTabContentsView(TabContents* tab_contents) {
   return new TabContentsViewMac(tab_contents);
 }
 }
 
 TabContentsViewMac::TabContentsViewMac(TabContents* tab_contents)
     : tab_contents_(tab_contents),
-      preferred_width_(0),
       overlaid_view_(nil) {
 }
 
 TabContentsViewMac::~TabContentsViewMac() {
   // This handles the case where a renderer close call was deferred
   // while the user was operating a UI control which resulted in a
   // close.  In that case, the Cocoa view outlives the
   // TabContentsViewMac instance due to Cocoa retain count.
   [cocoa_view_ cancelDeferredClose];
   [cocoa_view_ clearTabContentsView];
@@ skipping 529 matching lines @@
       [[[notification userInfo] objectForKey:kSelectionDirection]
         unsignedIntegerValue];
   if (direction == NSDirectSelection)
     return;
 
   [self tabContents]->
       FocusThroughTabTraversal(direction == NSSelectingPrevious);
 }
 
 @end