[Extensions] Migrate ExtensionInstallPrompt::Delegate to be a callback

chrome/browser/extensions/extension_install_prompt_test_helper.h

Index: chrome/browser/extensions/extension_install_prompt_test_helper.h
diff --git a/chrome/browser/extensions/extension_install_prompt_test_helper.h b/chrome/browser/extensions/extension_install_prompt_test_helper.h
new file mode 100644
index 0000000000000000000000000000000000000000..dd7d2a92a79db8d1a446ea6d6f24906943a67e78
--- /dev/null
+++ b/chrome/browser/extensions/extension_install_prompt_test_helper.h
@@ -0,0 +1,39 @@
+// Copyright 2015 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.
+
+#ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_INSTALL_PROMPT_TEST_HELPER_H_
+#define CHROME_BROWSER_EXTENSIONS_EXTENSION_INSTALL_PROMPT_TEST_HELPER_H_
+
+#include "base/macros.h"
+#include "chrome/browser/extensions/extension_install_prompt.h"
+
+// A helper class to be used with ExtensionInstallPrompt that keeps track of the
+// result. Note that this class does no lifetime management.
+class ExtensionInstallPromptTestHelper {
+ public:
+  ExtensionInstallPromptTestHelper();
+  explicit ExtensionInstallPromptTestHelper(const base::Closure& quit_closure);
+  ~ExtensionInstallPromptTestHelper();
+
+  // Returns a callback to be used with the ExtensionInstallPrompt.
+  ExtensionInstallPrompt::DoneCallback GetCallback();
+
+  // Note: This ADD_FAILURE()s if result_ has not been set.
+  ExtensionInstallPrompt::Result result() const;
+
+  bool has_result() const { return result_.get() != nullptr; }
+
+ private:
+  void HandleResult(ExtensionInstallPrompt::Result result);
+
+  scoped_ptr<ExtensionInstallPrompt::Result> result_;
+
+  // A closure to run once HandleResult() has been called; used for exiting
+  // run loops in tests.
+  base::Closure quit_closure_;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionInstallPromptTestHelper);
+};
+
+#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_INSTALL_PROMPT_TEST_HELPER_H_