New Task Manager - Phase 1.1: Implement Browser Process Task Providing

chrome/browser/task_management/providers/task_provider.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 "chrome/browser/task_management/providers/task_provider.h"
+
+namespace task_management {
+
+TaskProvider::TaskProvider()
+    : observer_(nullptr) {
+}
+
+TaskProvider::~TaskProvider() {
+}
+
+void TaskProvider::SetObserver(TaskProviderObserver* observer) {
+  DCHECK(observer);
+  DCHECK(!observer_);
+  observer_ = observer;
+  StartUpdating();
+}
+
+void TaskProvider::ClearObserver() {
+  DCHECK(observer_);
+  observer_ = nullptr;
+  StopUpdating();
+}
+
+void TaskProvider::NotifyObserverTaskAdded(Task* task) const {
+  DCHECK(observer_);

[Lei Zhang, 2015/04/01 22:47:51]

There's no real need to DCHECK a pointer right before dereferencing it.

[afakhry, 2015/04/03 01:51:01]

Yes but it would provide better debugging clues as to what went wrong as opposed
to just getting a SIGSEGV.

+  observer_->TaskAdded(task);
+}
+
+void TaskProvider::NotifyObserverTaskRemoved(Task* task) const {
+  DCHECK(observer_);
+  observer_->TaskRemoved(task);
+}
+
+}  // namespace task_management