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

chrome/browser/ui/cocoa/browser_window_cocoa.mm

Index: chrome/browser/ui/cocoa/browser_window_cocoa.mm
diff --git a/chrome/browser/ui/cocoa/browser_window_cocoa.mm b/chrome/browser/ui/cocoa/browser_window_cocoa.mm
index c23cf56cc423ee18383da201f53e1d4ee361bc42..84eebefe78d4b7222886ea46ca4596fdabff94c5 100644
--- a/chrome/browser/ui/cocoa/browser_window_cocoa.mm
+++ b/chrome/browser/ui/cocoa/browser_window_cocoa.mm
@@ -14,7 +14,6 @@
 #include "chrome/browser/download/download_shelf.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/profiles/profile.h"
-#include "chrome/browser/tab_contents/tab_contents_view_mac.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_list.h"
 #import "chrome/browser/ui/cocoa/browser/avatar_button_controller.h"
@@ -604,12 +603,6 @@ NSWindow* BrowserWindowCocoa::window() const {
   return [controller_ window];
 }
 
-void BrowserWindowCocoa::UpdatePreferredSize(content::WebContents* web_contents,
-                                             const gfx::Size& pref_size) {
-  static_cast<TabContentsViewMac*>(web_contents->GetView())->
-      set_preferred_width(pref_size.width());
-}
-
 void BrowserWindowCocoa::ShowAvatarBubble(WebContents* web_contents,
                                           const gfx::Rect& rect) {
   NSView* view = web_contents->GetNativeView();