Makes it so when NSViewControllers go away that they remove their views from ...

chrome/browser/cocoa/extension_shelf_controller.mm

 // Copyright (c) 2009 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 "extension_shelf_controller.h"
 
 #include "base/mac_util.h"
 #include "chrome/browser/browser.h"
 #include "chrome/browser/extensions/extension_shelf_model.h"
 #include "skia/ext/skia_utils_mac.h"
@@ skipping 310 matching lines @@
     browser_ = browser;
     shelfHeight_ = [[self view] bounds].size.height;
 
     NSRect frame = [[self view] frame];
     frame.size.height = 0;
     [[self view] setFrame:frame];
   }
   return self;
 }
 
+- (void)dealloc {
+  // Remove our view from its superview so it doesn't attempt to reference
+  // it when the controller is gone.
+  [[self view] removeFromSuperview];
+  [super dealloc];
+}
+
 - (void)wasInsertedIntoWindow {
   // The bridge_ calls cacheDisplayInRect:toBitmapImageRep:, which requires that
   // the view is in a superview to work. Hence, create the bridge object no
   // sooner.
   DCHECK(bridge_.get() == NULL);
   bridge_.reset(new ExtensionShelfMac(browser_, self));
 }
 
 - (IBAction)show:(id)sender {
   [resizeDelegate_ resizeView:[self view] newHeight:shelfHeight_];
 }
 
 - (IBAction)hide:(id)sender {
   [resizeDelegate_ resizeView:[self view] newHeight:0];
 }
 
 - (CGFloat)height {
   return shelfHeight_;
 }
 
 - (void)updateVisibility:(id)sender {
   if(bridge_.get())
     bridge_->AdjustHeight();
 }
 
 @end