Bug 1323076 - Part 2: EventDispatcher with flag checking for TaskTracer. r=smaug

dom/events/Event.cpp

@@ -245,24 +245,11 @@ Event::WrapObjectInternal(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
 NS_IMETHODIMP
 Event::GetType(nsAString& aType)
 {
-  if (!mIsMainThreadEvent || !mEvent->mSpecifiedEventTypeString.IsEmpty()) {
+  if (!mIsMainThreadEvent) {
     aType = mEvent->mSpecifiedEventTypeString;
     return NS_OK;
   }
-  const char* name = GetEventName(mEvent->mMessage);
-
-  if (name) {
-    CopyASCIItoUTF16(name, aType);
-    return NS_OK;
-  } else if (mEvent->mMessage == eUnidentifiedEvent &&
-             mEvent->mSpecifiedEventType) {
-    // Remove "on"
-    aType = Substring(nsDependentAtomString(mEvent->mSpecifiedEventType), 2);
-    mEvent->mSpecifiedEventTypeString = aType;
-    return NS_OK;
-  }
-
-  aType.Truncate();
+  GetWidgetEventType(mEvent, aType);
   return NS_OK;
 }
 
@@ -1291,6 +1278,30 @@ Event::GetShadowRelatedTarget(nsIContent* aCurrentTarget,
   return nullptr;
 }
 
+void
+Event::GetWidgetEventType(WidgetEvent* aEvent, nsAString& aType)
+{
+  if (!aEvent->mSpecifiedEventTypeString.IsEmpty()) {
+    aType = aEvent->mSpecifiedEventTypeString;
+    return;
+  }
+
+  const char* name = GetEventName(aEvent->mMessage);
+
+  if (name) {
+    CopyASCIItoUTF16(name, aType);
+    return;
+  } else if (aEvent->mMessage == eUnidentifiedEvent &&
+             aEvent->mSpecifiedEventType) {
+    // Remove "on"
+    aType = Substring(nsDependentAtomString(aEvent->mSpecifiedEventType), 2);
+    aEvent->mSpecifiedEventTypeString = aType;
+    return;
+  }
+
+  aType.Truncate();
+}
+
 NS_IMETHODIMP
 Event::GetCancelBubble(bool* aCancelBubble)
 {

dom/events/Event.h

@@ -265,6 +265,14 @@ public:
     mEvent->mSpecifiedEventType = nullptr;
   }
 
+  /**
+   * For WidgetEvent, return it's type in string.
+   *
+   * @param aEvent is a WidgetEvent to get its type.
+   * @param aType is a string where to return the type.
+   */
+  static void GetWidgetEventType(WidgetEvent* aEvent, nsAString& aType);
+
 protected:
 
   // Internal helper functions

dom/events/EventDispatcher.cpp

@@ -64,6 +64,7 @@
 #ifdef MOZ_TASK_TRACER
 #include "GeckoTaskTracer.h"
 #include "mozilla/dom/Element.h"
+#include "mozilla/Likely.h"
 using namespace mozilla::tasktracer;
 #endif
 
@@ -606,23 +607,27 @@ EventDispatcher::Dispatch(nsISupports* aTarget,
                  NS_ERROR_DOM_INVALID_STATE_ERR);
 
 #ifdef MOZ_TASK_TRACER
-  {
+  if (MOZ_UNLIKELY(mozilla::tasktracer::IsStartLogging())) {
+    nsAutoCString eventType;
+    nsAutoString eventTypeU16;
     if (aDOMEvent) {
-      nsAutoString eventType;
-      aDOMEvent->GetType(eventType);
-
-      nsCOMPtr<Element> element = do_QueryInterface(aTarget);
-      nsAutoString elementId;
-      nsAutoString elementTagName;
-      if (element) {
-        element->GetId(elementId);
-        element->GetTagName(elementTagName);
-      }
-      AddLabel("Event [%s] dispatched at target [id:%s tag:%s]",
-               NS_ConvertUTF16toUTF8(eventType).get(),
-               NS_ConvertUTF16toUTF8(elementId).get(),
-               NS_ConvertUTF16toUTF8(elementTagName).get());
+      aDOMEvent->GetType(eventTypeU16);
+    } else {
+      Event::GetWidgetEventType(aEvent, eventTypeU16);
     }
+    eventType = NS_ConvertUTF16toUTF8(eventTypeU16);
+
+    nsCOMPtr<Element> element = do_QueryInterface(aTarget);
+    nsAutoString elementId;
+    nsAutoString elementTagName;
+    if (element) {
+      element->GetId(elementId);
+      element->GetTagName(elementTagName);
+    }
+    AddLabel("Event [%s] dispatched at target [id:%s tag:%s]",
+             eventType.get(),
+             NS_ConvertUTF16toUTF8(elementId).get(),
+             NS_ConvertUTF16toUTF8(elementTagName).get());
   }
 #endif