Fix DevToolsManagerTest.TestObserver flakiness.

content/browser/devtools/devtools_manager.cc

 // Copyright (c) 2012 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/browser/devtools/devtools_manager.h"
 
 #include "base/bind.h"
 #include "base/message_loop/message_loop.h"
 #include "content/browser/devtools/devtools_agent_host_impl.h"
 #include "content/browser/devtools/devtools_netlog_observer.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/devtools_target.h"
 
 namespace content {
 
+namespace {
+
+int kObserverThrottleInterval = 500; // ms
+
+}  // namespace
+
 // static
 DevToolsManager* DevToolsManager::GetInstance() {
   return Singleton<DevToolsManager>::get();
 }
 
 DevToolsManager::DevToolsManager()
     : delegate_(GetContentClient()->browser()->GetDevToolsManagerDelegate()),
       update_target_list_required_(false),
       update_target_list_scheduled_(false),
       update_target_list_callback_(base::Bind(
@@ skipping 57 matching lines @@
     UpdateTargetListThrottled();
 }
 
 void DevToolsManager::UpdateTargetListThrottled() {
   if (!update_target_list_required_) {
     update_target_list_scheduled_ = false;
     return;
   }
 
   update_target_list_scheduled_ = true;
-  base::MessageLoop::current()->PostDelayedTask(
-      FROM_HERE,
-      update_target_list_callback_.callback(),
-      observer_throttle_interval_);
+  if (scheduler_.is_null()) {
+    base::MessageLoop::current()->PostDelayedTask(
+        FROM_HERE,
+        update_target_list_callback_.callback(),
+        base::TimeDelta::FromMilliseconds(kObserverThrottleInterval));
+  } else {
+    scheduler_.Run(update_target_list_callback_.callback());
+  }
 
   update_target_list_required_ = false;
   if (!delegate_) {
     Observer::TargetList empty_list;
     NotifyTargetListChanged(empty_list);
     return;
   }
   delegate_->EnumerateTargets(base::Bind(
       &DevToolsManager::NotifyTargetListChanged,
       base::Unretained(this)));
 }
 
 void DevToolsManager::NotifyTargetListChanged(
     const Observer::TargetList& targets) {
   FOR_EACH_OBSERVER(Observer, observer_list_, TargetListChanged(targets));
   STLDeleteContainerPointers(targets.begin(), targets.end());
 }
 
-// static
-base::TimeDelta DevToolsManager::observer_throttle_interval_ =
-    base::TimeDelta::FromMilliseconds(500);
-
-// static
-void DevToolsManager::SetObserverThrottleIntervalForTest(
-    base::TimeDelta interval) {
-  observer_throttle_interval_ = interval;
+void DevToolsManager::SetSchedulerForTest(Scheduler scheduler) {
+  scheduler_ = scheduler;
 }
 
 }  // namespace content