sync: Refactor StatusChangeChecker hierarchy

chrome/browser/sync/test/integration/status_change_checker.cc

 // Copyright 2013 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/sync/test/integration/status_change_checker.h"
 
-StatusChangeChecker::StatusChangeChecker() {}
+#include "base/logging.h"
+#include "base/message_loop/message_loop.h"
+#include "base/timer/timer.h"
+
+StatusChangeChecker::StatusChangeChecker()
+  : timed_out_(false),
+    wait_started_(false) {}
 
 StatusChangeChecker::~StatusChangeChecker() {}
+
+bool StatusChangeChecker::TimedOut() const {
+  return timed_out_;
+}
+
+base::TimeDelta StatusChangeChecker::GetTimeoutDuration() {
+  return base::TimeDelta::FromSeconds(45);
+}
+
+void StatusChangeChecker::StartBlockingWait() {
+  DCHECK(!wait_started_) << "This class is intended for one use only.";
+  wait_started_ = true;
+
+  base::OneShotTimer<StatusChangeChecker> timer;
+  timer.Start(FROM_HERE,
+              GetTimeoutDuration(),
+              base::Bind(&StatusChangeChecker::OnTimeout,
+                         base::Unretained(this)));
+
+  {
+    base::MessageLoop* loop = base::MessageLoop::current();
+    base::MessageLoop::ScopedNestableTaskAllower allow(loop);
+    loop->Run();
+  }
+}
+
+void StatusChangeChecker::StopWaiting() {
+  base::MessageLoop::current()->QuitWhenIdle();
+}
+
+void StatusChangeChecker::CheckExitCondition() {
+  DVLOG(1) << "Await -> Checking Condition: " << GetDebugMessage();
+  if (IsExitConditionSatisfied()) {
+    DVLOG(1) << "Await -> Condition met: " << GetDebugMessage();
+    StopWaiting();
+  }
+}
+
+void StatusChangeChecker::OnTimeout() {
+  DVLOG(1) << "Await -> Timed out: " << GetDebugMessage();
+  timed_out_ = true;
+  StopWaiting();
+}