Clean up TCW, make it solely a hub for 1:1 observer/helper objects.

chrome/browser/ui/cocoa/constrained_window_mac.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 "chrome/browser/ui/cocoa/constrained_window_mac.h"
 
 #import "chrome/browser/ui/cocoa/browser_window_controller.h"
 #include "chrome/browser/ui/constrained_window_tab_helper.h"
 #include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
 #include "content/browser/tab_contents/tab_contents.h"
@@ skipping 87 matching lines @@
   wrapper->constrained_window_tab_helper()->AddConstrainedDialog(this);
 }
 
 ConstrainedWindowMac::~ConstrainedWindowMac() {}
 
 void ConstrainedWindowMac::ShowConstrainedWindow() {
   should_be_visible_ = true;
   // The TabContents only has a native window if it is currently visible. In
   // this case, open the sheet now. Else, Realize() will be called later, when
   // our tab becomes visible.
-  NSWindow* browserWindow = wrapper_->view()->GetTopLevelNativeWindow();
+  NSWindow* browserWindow =
+      wrapper_->tab_contents()->view()->GetTopLevelNativeWindow();
   NSWindowController* controller = [browserWindow windowController];
   if (controller != nil) {
     DCHECK([controller isKindOfClass:[BrowserWindowController class]]);
     BrowserWindowController* browser_controller =
         static_cast<BrowserWindowController*>(controller);
     if ([browser_controller canAttachConstrainedWindow])
       Realize(browser_controller);
   }
 }
 
@@ skipping 24 matching lines @@
     return;
   }
   DCHECK(controller != nil);
 
   // Remember the controller we're adding ourselves to, so that we can later
   // remove us from it.
   controller_ = controller;
   [controller_ attachConstrainedWindow:this];
   delegate_->set_sheet_open(true);
 }