Add devtools trace event for event dispatching

Source/core/events/EventDispatcher.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 15 matching lines @@
 #include "config.h"
 #include "core/events/EventDispatcher.h"
 
 #include "core/dom/ContainerNode.h"
 #include "core/events/EventDispatchMediator.h"
 #include "core/events/MouseEvent.h"
 #include "core/events/ScopedEventQueue.h"
 #include "core/events/WindowEventContext.h"
 #include "core/frame/FrameView.h"
 #include "core/inspector/InspectorInstrumentation.h"
+#include "platform/TraceEvent.h"
 #include "wtf/RefPtr.h"
 
 namespace WebCore {
 
 static HashSet<Node*>* gNodesDispatchingSimulatedClicks = 0;
 
 bool EventDispatcher::dispatchEvent(Node* node, PassRefPtr<EventDispatchMediator> mediator)
 {
     TRACE_EVENT0("webkit", "EventDispatcher::dispatchEvent");
     ASSERT(!NoEventDispatchAssertion::isEventDispatchForbidden());
@@ skipping 59 matching lines @@
 #ifndef NDEBUG
     ASSERT(!m_eventDispatched);
     m_eventDispatched = true;
 #endif
     ChildNodesLazySnapshot::takeChildNodesLazySnapshot();
 
     m_event->setTarget(EventPath::eventTargetRespectingTargetRules(m_node.get()));
     ASSERT(!NoEventDispatchAssertion::isEventDispatchForbidden());
     ASSERT(m_event->target());
     WindowEventContext windowEventContext(m_event.get(), m_node.get(), topNodeEventContext());
+    TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("devtools-timeline"), "EventDispatcher::dispatch", "type", TRACE_STR_COPY(m_event->type().ascii().data()));

[pfeldman, 2014/04/16 09:01:19]

"EventDispatcher::dispatchEvent"

[yurys, 2014/04/18 13:38:52]

Why? The method is called dispatch. I believe we should use either method name
as the trace event name or front-end name for that event, i.e. non-qualified
"EventDispatch".

+    // FIXME(361045): remove InspectorInstrumentation calls once DevTools Timeline migrated on tracing.

[pfeldman, 2014/04/16 09:01:19]

migrates to tracing.

[yurys, 2014/04/18 13:38:52]

Done.

     InspectorInstrumentationCookie cookie = InspectorInstrumentation::willDispatchEvent(&m_node->document(), *m_event, windowEventContext.window(), m_node.get(), m_event->eventPath());
 
     void* preDispatchEventHandlerResult;
     if (dispatchEventPreProcess(preDispatchEventHandlerResult) == ContinueDispatching)
         if (dispatchEventAtCapturing(windowEventContext) == ContinueDispatching)
             if (dispatchEventAtTarget() == ContinueDispatching)
                 dispatchEventAtBubbling(windowEventContext);
     dispatchEventPostProcess(preDispatchEventHandlerResult);
 
     // Ensure that after event dispatch, the event's target object is the
@@ skipping 94 matching lines @@
         }
     }
 }
 
 const NodeEventContext* EventDispatcher::topNodeEventContext()
 {
     return m_event->eventPath().isEmpty() ? 0 : &m_event->eventPath().last();
 }
 
 }