scheduler: Implement WebFrameScheduler and WebPageScheduler

components/scheduler/renderer/web_frame_host_scheduler_impl.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 "components/scheduler/renderer/web_frame_host_scheduler_impl.h"
+
+#include "base/logging.h"
+#include "components/scheduler/renderer/web_frame_scheduler_impl.h"
+
+namespace scheduler {
+
+WebFrameHostSchedulerImpl::WebFrameHostSchedulerImpl(
+    RendererScheduler* render_scheduler)
+    : render_scheduler_(render_scheduler), background_(false) {}
+
+WebFrameHostSchedulerImpl::~WebFrameHostSchedulerImpl() {
+  DCHECK(frame_schedulers_.empty()) << "WebFrameHostSchedulerImpl should "
+                                       "outlive its WebFrameSchedulers";
+}
+
+void WebFrameHostSchedulerImpl::setPageInBackground(bool background) {
+  background_ = background;
+  // TODO(alexclarke): Do something with this flag.
+}
+
+blink::WebFrameScheduler* WebFrameHostSchedulerImpl::createFrameScheduler() {
+  WebFrameSchedulerImpl* frame_scheduler =
+      new WebFrameSchedulerImpl(render_scheduler_, this);
+  frame_schedulers_.insert(frame_scheduler);
+  return frame_scheduler;
+}
+
+void WebFrameHostSchedulerImpl::Unregister(
+    WebFrameSchedulerImpl* frame_scheduler) {
+  DCHECK(frame_schedulers_.find(frame_scheduler) != frame_schedulers_.end());
+  frame_schedulers_.erase(frame_scheduler);
+}
+
+}  // namespace scheduler