[Extensions] Small cleanup of extension_install_prompt.*

chrome/browser/extensions/external_install_error.cc

 // Copyright 2014 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/extensions/external_install_error.h"
 
 #include <stddef.h>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 13 matching lines @@
 #include "chrome/browser/ui/global_error/global_error_service_factory.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/grit/generated_resources.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/browser/extension_system.h"
 #include "extensions/browser/uninstall_reason.h"
 #include "extensions/common/constants.h"
 #include "extensions/common/extension.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/gfx/image/image.h"
+#include "ui/gfx/image/image_skia.h"
 #include "ui/gfx/image/image_skia_operations.h"
 
 namespace extensions {
 
 namespace {
 
 // Return the menu label for a global error.
 base::string16 GetMenuItemLabel(const Extension* extension) {
   if (!extension)
     return base::string16();
@@ skipping 377 matching lines @@
     if (browser)
       global_error_->ShowBubbleView(browser);
   } else {
     DCHECK(alert_type_ == MENU_ALERT);
     global_error_.reset(new ExternalInstallMenuAlert(this));
     error_service_->AddGlobalError(global_error_.get());
   }
 }
 
 }  // namespace extensions