Add a regression test for the CardUnmaskPrompt.

chrome/browser/ui/views/autofill/card_unmask_prompt_view_tester_views.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/ui/views/autofill/card_unmask_prompt_view_tester_views.h"
+
+#include "chrome/browser/ui/views/autofill/card_unmask_prompt_views.h"
+
+namespace autofill {
+
+// static
+scoped_ptr<CardUnmaskPromptViewTester> CardUnmaskPromptViewTester::For(
+    CardUnmaskPromptView* view) {
+  return scoped_ptr<CardUnmaskPromptViewTester>(
+      new CardUnmaskPromptViewTesterViews(
+          static_cast<CardUnmaskPromptViews*>(view)));
+}
+
+// Class that facilitates testing.
+CardUnmaskPromptViewTesterViews::CardUnmaskPromptViewTesterViews(
+    CardUnmaskPromptViews* view)
+    : view_(view) {
+}
+
+CardUnmaskPromptViewTesterViews::~CardUnmaskPromptViewTesterViews() {
+}
+
+void CardUnmaskPromptViewTesterViews::Close() {
+  view_->ClosePrompt();
+}
+
+}  // namespace autofill