Add a trace event for running microtasks

sky/engine/core/dom/Microtask.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 15 matching lines @@
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "sky/engine/config.h"
 #include "sky/engine/core/dom/Microtask.h"
 
 #include "base/bind.h"
 #include "sky/engine/bindings/core/v8/V8PerIsolateData.h"
+#include "sky/engine/platform/TraceEvent.h"
 #include "sky/engine/public/platform/WebThread.h"
 #include "v8/include/v8.h"
 
 namespace blink {
 
 namespace {
 
 class Task : public WebThread::Task {
 public:
     explicit Task(const base::Closure& closure)
@@ skipping 12 matching lines @@
 
 }
 
 void Microtask::performCheckpoint()
 {
     v8::Isolate* isolate = v8::Isolate::GetCurrent();
     V8PerIsolateData* isolateData = V8PerIsolateData::from(isolate);
     ASSERT(isolateData);
     if (isolateData->recursionLevel() || isolateData->performingMicrotaskCheckpoint())
         return;
+    TRACE_EVENT0("v8", "v8.runMicrotasks");
     isolateData->setPerformingMicrotaskCheckpoint(true);
     isolate->RunMicrotasks();
     isolateData->setPerformingMicrotaskCheckpoint(false);
 }
 
 static void microtaskFunctionCallback(void* data)
 {
     OwnPtr<WebThread::Task> task = adoptPtr(static_cast<WebThread::Task*>(data));
     task->run();
 }
 
 void Microtask::enqueueMicrotask(PassOwnPtr<WebThread::Task> callback)
 {
     v8::Isolate* isolate = v8::Isolate::GetCurrent();
     isolate->EnqueueMicrotask(&microtaskFunctionCallback, callback.leakPtr());
 }
 
 void Microtask::enqueueMicrotask(const base::Closure& callback)
 {
     enqueueMicrotask(adoptPtr(new Task(callback)));
 }
 
 } // namespace blink