Make ExtensionInstallPrompt::Prompt ref-counted

chrome/browser/ui/cocoa/extensions/extension_install_prompt_test_utils.mm

 // Copyright (c) 2012 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 "chrome/browser/ui/cocoa/extensions/extension_install_prompt_test_utils.h"
 
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "base/json/json_file_value_serializer.h"
 #include "base/path_service.h"
@@ skipping 53 matching lines @@
              .AppendASCII("icon.png");
 
   std::string file_contents;
   base::ReadFileToString(path, &file_contents);
 
   return gfx::Image::CreateFrom1xPNGBytes(
       reinterpret_cast<const unsigned char*>(file_contents.c_str()),
       file_contents.length());
 }
 
-ExtensionInstallPrompt::Prompt BuildExtensionInstallPrompt(
+scoped_refptr<ExtensionInstallPrompt::Prompt> BuildExtensionInstallPrompt(
     Extension* extension) {
-  ExtensionInstallPrompt::Prompt prompt(ExtensionInstallPrompt::INSTALL_PROMPT);
-  prompt.set_extension(extension);
-  prompt.set_icon(LoadInstallPromptIcon());
+  scoped_refptr<ExtensionInstallPrompt::Prompt> prompt =
+      new ExtensionInstallPrompt::Prompt(
+          ExtensionInstallPrompt::INSTALL_PROMPT);
+  prompt->set_extension(extension);
+  prompt->set_icon(LoadInstallPromptIcon());
   return prompt;
 }
 
-ExtensionInstallPrompt::Prompt BuildExtensionPostInstallPermissionsPrompt(
-    Extension* extension) {
-  ExtensionInstallPrompt::Prompt prompt(
-      ExtensionInstallPrompt::POST_INSTALL_PERMISSIONS_PROMPT);
-  prompt.set_extension(extension);
-  prompt.set_icon(LoadInstallPromptIcon());
+scoped_refptr<ExtensionInstallPrompt::Prompt>
+BuildExtensionPostInstallPermissionsPrompt(Extension* extension) {
+  scoped_refptr<ExtensionInstallPrompt::Prompt> prompt =
+      new ExtensionInstallPrompt::Prompt(
+          ExtensionInstallPrompt::POST_INSTALL_PERMISSIONS_PROMPT);
+  prompt->set_extension(extension);
+  prompt->set_icon(LoadInstallPromptIcon());
   return prompt;
 }
 
 }  // namespace chrome