scheduler: Implement task observers

content/renderer/scheduler/webthread_impl_for_scheduler.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/renderer/scheduler/webthread_impl_for_scheduler.h"
+
+#include "content/renderer/scheduler/renderer_scheduler.h"
+#include "third_party/WebKit/public/platform/WebTraceLocation.h"
+
+namespace content {
+
+WebThreadImplForScheduler::WebThreadImplForScheduler(
+    RendererScheduler* scheduler)
+    : task_runner_(scheduler->DefaultTaskRunner()),
+      scheduler_(scheduler),
+      thread_id_(base::PlatformThread::CurrentId()) {
+}
+
+WebThreadImplForScheduler::~WebThreadImplForScheduler() {

[rmcilroy, 2015/02/13 12:53:22]

Could we just replace WebThreadImplForMessageLoop with this?  If not, could we
just extend it and override on Add/RemoveTaskObserverInternal?

[Sami, 2015/02/13 14:27:26]

Ok, I'll roll my WebThread refactor into this patch since the end result is much
cleaner that way :)

+}
+
+void WebThreadImplForScheduler::postTask(Task* task) {
+  postDelayedTask(task, 0);
+}
+
+void WebThreadImplForScheduler::postTask(
+    const blink::WebTraceLocation& location,
+    Task* task) {
+  postDelayedTask(location, task, 0);
+}
+
+void WebThreadImplForScheduler::postDelayedTask(Task* task,
+                                                long long delay_ms) {
+  task_runner_->PostDelayedTask(
+      FROM_HERE,
+      base::Bind(RunWebThreadTask, base::Passed(make_scoped_ptr(task))),
+      base::TimeDelta::FromMilliseconds(delay_ms));
+}
+
+void WebThreadImplForScheduler::postDelayedTask(
+    const blink::WebTraceLocation& web_location,
+    Task* task,
+    long long delay_ms) {
+  tracked_objects::Location location(web_location.functionName(),
+                                     web_location.fileName(), -1, nullptr);
+  task_runner_->PostDelayedTask(
+      location,
+      base::Bind(RunWebThreadTask, base::Passed(make_scoped_ptr(task))),
+      base::TimeDelta::FromMilliseconds(delay_ms));
+}
+
+void WebThreadImplForScheduler::enterRunLoop() {
+  CHECK(isCurrentThread());
+  // We don't support nesting.
+  CHECK(!base::MessageLoop::current()->is_running());
+  base::MessageLoop::current()->Run();
+}
+
+void WebThreadImplForScheduler::exitRunLoop() {
+  CHECK(isCurrentThread());
+  CHECK(base::MessageLoop::current()->is_running());
+  base::MessageLoop::current()->Quit();
+}
+
+bool WebThreadImplForScheduler::isCurrentThread() const {
+  return task_runner_->BelongsToCurrentThread();
+}
+
+blink::PlatformThreadId WebThreadImplForScheduler::threadId() const {
+  return thread_id_;
+}
+
+void WebThreadImplForScheduler::AddTaskObserverInternal(
+    base::MessageLoop::TaskObserver* observer) {
+  scheduler_->AddTaskObserver(observer);
+}
+
+void WebThreadImplForScheduler::RemoveTaskObserverInternal(
+    base::MessageLoop::TaskObserver* observer) {
+  scheduler_->RemoveTaskObserver(observer);
+}
+
+}  // namespace content