Add support code to test the cast system tray item.

ash/test/tray_cast_test_api.cc

Index: ash/test/tray_cast_test_api.cc
diff --git a/ash/test/tray_cast_test_api.cc b/ash/test/tray_cast_test_api.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e575a4a775bf2039a17289445942feaaac44fe15
--- /dev/null
+++ b/ash/test/tray_cast_test_api.cc
@@ -0,0 +1,47 @@
+// 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 "ash/test/tray_cast_test_api.h"
+
+#include "ui/views/view.h"
+
+namespace ash {
+
+TrayCastTestAPI::TrayCastTestAPI(TrayCast* tray_cast) : tray_cast_(tray_cast) {
+}
+
+TrayCastTestAPI::~TrayCastTestAPI() {
+}
+
+bool TrayCastTestAPI::IsTrayInitialized() const {
+  return tray_cast_->default_ != nullptr;
+}
+
+bool TrayCastTestAPI::IsTrayVisible() const {
+  views::View* tray_view =
+      tray_cast_->FindChildViewForTest(TrayCast::TRAY_VIEW);
+  return tray_view != nullptr && tray_view->IsDrawn();
+}
+
+bool TrayCastTestAPI::IsTrayCastViewVisible() const {
+  return tray_cast_->FindChildViewForTest(TrayCast::CAST_VIEW)->IsDrawn();
+}
+
+bool TrayCastTestAPI::IsTraySelectViewVisible() const {
+  return tray_cast_->FindChildViewForTest(TrayCast::SELECT_VIEW)->IsDrawn();
+}
+
+void TrayCastTestAPI::StartCast(const std::string& receiver_id) {
+  return tray_cast_->StartCastForTest(receiver_id);
+}
+
+void TrayCastTestAPI::StopCast() {
+  return tray_cast_->StopCastForTest();
+}
+
+void TrayCastTestAPI::OnCastingSessionStartedOrStopped(bool is_casting) {
+  tray_cast_->OnCastingSessionStartedOrStopped(is_casting);
+}
+
+}  // namespace ash