Retry to add MockPresentationClient to use in layout tests.

content/shell/renderer/test_runner/mock_presentation_client.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_client.h"
+
+#include "base/logging.h"
+#include "third_party/WebKit/public/platform/modules/presentation/WebPresentationController.h"
+
+namespace content {
+
+MockPresentationClient::MockPresentationClient()
+    : controller_(nullptr),
+      screen_availability_(false) {
+}
+
+MockPresentationClient::~MockPresentationClient() {
+}
+
+void MockPresentationClient::SetScreenAvailability(bool available) {
+  if (screen_availability_ == available)
+    return;
+  screen_availability_ = available;
+
+  if (!controller_)
+    return;
+  if (!controller_->isAvailableChangeWatched())
+    return;
+  controller_->didChangeAvailability(screen_availability_);
+}
+
+void MockPresentationClient::setController(
+    blink::WebPresentationController* controller) {
+  controller_ = controller;

[Peter Beverloo, 2015/02/09 17:40:32]

I don't like removing the DCHECK() here because you do have the DCHECK in the
PresentationController. The lifetime constraints of objects should be identical.

You can add a line to TestRunner::Reset() (in the delegate_ section), but
ideally fix Blink to properly nullify the controller after the testing page is
done.

[whywhat, 2015/02/12 16:30:47]

Acknowledged.

+  if (controller_)
+    updateAvailableChangeWatched(controller_->isAvailableChangeWatched());
+}
+
+void MockPresentationClient::updateAvailableChangeWatched(bool watched) {
+  if (!watched)
+    return;
+  DCHECK(controller_);
+  if (screen_availability_)
+    controller_->didChangeAvailability(screen_availability_);
+}
+
+}  // namespace content