Retry to add MockPresentationClient to use in layout tests.

content/shell/renderer/test_runner/mock_presentation_service.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 "content/shell/renderer/test_runner/mock_presentation_service.h"
+
+#include "base/logging.h"
+
+namespace content {
+
+MockPresentationService::MockPresentationService()
+    : screen_availability_(false) {
+}
+
+MockPresentationService::~MockPresentationService() {
+  Reset();
+}
+
+void MockPresentationService::SetScreenAvailability(bool available) {
+  if (screen_availability_ == available)
+    return;
+  screen_availability_ = available;
+
+  FOR_EACH_OBSERVER(
+      MockPresentationClient,
+      presentation_clients_,
+      SetScreenAvailability(available));
+}
+
+void MockPresentationService::Reset() {
+  FOR_EACH_OBSERVER(MockPresentationClient, presentation_clients_, Reset());
+  presentation_clients_.Clear();
+  screen_availability_ = false;
+}
+
+void MockPresentationService::RegisterPresentationClientMock(
+    MockPresentationClient* client) {
+  DCHECK(client);
+  presentation_clients_.AddObserver(client);
+}
+
+void MockPresentationService::UnregisterPresentationClientMock(
+    MockPresentationClient* client) {
+  DCHECK(client);
+  presentation_clients_.RemoveObserver(client);
+}
+
+}  // namespace content