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

chrome/browser/extensions/extension_install_prompt_test_helper.cc

+// 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.
+
+#include "chrome/browser/extensions/extension_install_prompt_test_helper.h"
+
+#include "base/bind.h"
+#include "base/callback_helpers.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+ExtensionInstallPromptTestHelper::ExtensionInstallPromptTestHelper() {}
+ExtensionInstallPromptTestHelper::ExtensionInstallPromptTestHelper(
+    const base::Closure& quit_closure) : quit_closure_(quit_closure) {}
+ExtensionInstallPromptTestHelper::~ExtensionInstallPromptTestHelper() {}
+
+ExtensionInstallPrompt::DoneCallback
+ExtensionInstallPromptTestHelper::GetCallback() {
+  return base::Bind(&ExtensionInstallPromptTestHelper::HandleResult,
+                    base::Unretained(this));
+}
+
+ExtensionInstallPrompt::Result
+ExtensionInstallPromptTestHelper::result() const {
+  if (!result_.get()) {
+    ADD_FAILURE() << "Result was never set!";
+    return ExtensionInstallPrompt::Result::ACCEPTED;  // Avoid crashing.
+  }
+  return *result_;
+}
+
+void ExtensionInstallPromptTestHelper::HandleResult(
+    ExtensionInstallPrompt::Result result) {
+  if (result_.get())
+    ADD_FAILURE() << "HandleResult() called twice!";
+  if (!quit_closure_.is_null())
+    base::ResetAndReturn(&quit_closure_).Run();
+  result_.reset(new ExtensionInstallPrompt::Result(result));
+}