Fixes crash in launcher. Some tests don't end up creating a delegate,

ui/aura_shell/launcher/launcher_view.cc

 // 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 "ui/aura_shell/launcher/launcher_view.h"
 
 #include "base/utf_string_conversions.h"
 #include "grit/ui_resources.h"
 #include "ui/aura/window.h"
 #include "ui/aura_shell/launcher/app_launcher_button.h"
@@ skipping 187 matching lines @@
 }
 
 LauncherView::~LauncherView() {
   model_->RemoveObserver(this);
 }
 
 void LauncherView::Init() {
   model_->AddObserver(this);
   ResourceBundle& rb = ResourceBundle::GetSharedInstance();
   new_browser_button_ = new views::ImageButton(this);
-  int new_browser_button_image_id =
-      Shell::GetInstance()->delegate()->GetResourceIDForNewBrowserWindow();
+  ShellDelegate* delegate = Shell::GetInstance()->delegate();
+  int new_browser_button_image_id = delegate ?
+      delegate->GetResourceIDForNewBrowserWindow() :
+      IDR_AURA_LAUNCHER_ICON_CHROME;
   new_browser_button_->SetImage(
       views::CustomButton::BS_NORMAL,
       rb.GetImageNamed(new_browser_button_image_id).ToSkBitmap());
   ConfigureChildView(new_browser_button_);
   AddChildView(new_browser_button_);
 
   const LauncherItems& items(model_->items());
   for (LauncherItems::const_iterator i = items.begin(); i != items.end(); ++i) {
     views::View* child = CreateViewForItem(*i);
     child->SetPaintToLayer(true);
@@ skipping 355 matching lines @@
   } else {
     int view_index = view_model_->GetIndexOfView(sender);
     // May be -1 while in the process of animating closed.
     if (view_index != -1)
       delegate->LauncherItemClicked(model_->items()[view_index]);
   }
 }
 
 }  // namespace internal
 }  // namespace aura_shell