Add synthetic delay testing framework

cc/resources/worker_pool.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 "cc/resources/worker_pool.h"
 
 #include <algorithm>
 #include <queue>
 
 #include "base/bind.h"
 #include "base/containers/hash_tables.h"
+#include "base/debug/synthetic_delay.h"
 #include "base/debug/trace_event.h"
 #include "base/strings/stringprintf.h"
 #include "base/synchronization/condition_variable.h"
 #include "base/threading/simple_thread.h"
 #include "base/threading/thread_restrictions.h"
 #include "cc/base/scoped_ptr_deque.h"
 
 namespace cc {
 
 namespace internal {
@@ skipping 311 matching lines @@
 
     // There may be more work available, so wake up another worker thread.
     has_ready_to_run_tasks_cv_.Signal();
 
     // Call WillRun() before releasing |lock_| and running task.
     task->WillRun();
 
     {
       base::AutoUnlock unlock(lock_);
 
+      SYNTHETIC_DELAY_BEGIN("cc.worker_pool_task");
       task->RunOnWorkerThread(thread_index);
+      SYNTHETIC_DELAY_END("cc.worker_pool_task");
     }
 
     // This will mark task as finished running.
     task->DidRun();
 
     // Now iterate over all dependents to remove dependency and check
     // if they are ready to run.
     scoped_ptr<internal::GraphNode> node = running_tasks_.take_and_erase(
         task.get());
     if (node) {
@@ skipping 70 matching lines @@
 void WorkerPool::SetTaskGraph(TaskGraph* graph) {
   TRACE_EVENT1("cc", "WorkerPool::SetTaskGraph",
                "num_tasks", graph->size());
 
   DCHECK(!in_dispatch_completion_callbacks_);
 
   inner_->SetTaskGraph(graph);
 }
 
 }  // namespace cc