[XHR] Decrease readyStateChange event dispatching during loading.

third_party/WebKit/Source/core/xmlhttprequest/XMLHttpRequestProgressEventThrottle.h

 /*
  * Copyright (C) 2010 Julien Chaffraix <jchaffraix@webkit.org>
  * All right 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 53 matching lines @@
     };
 
     // Dispatches a ProgressEvent.
     //
     // Special treatment for events named "progress" is implemented to dispatch
     // them at the required frequency. If this object is suspended, the given
     // ProgressEvent overwrites the existing. I.e. only the latest one gets
     // queued. If the timer is running, this method just updates
     // m_lengthComputable, m_loaded and m_total. They'll be used on next
     // fired() call.
+    // For an event named "progress", a readyStateChange will be dispatched
+    // as well.
     void dispatchProgressEvent(const AtomicString&, bool lengthComputable, unsigned long long loaded, unsigned long long total);
     // Dispatches the given event after operation about the "progress" event
     // depending on the value of the ProgressEventAction argument.
     void dispatchReadyStateChangeEvent(PassRefPtrWillBeRawPtr<Event>, DeferredEventAction);
 
     void suspend();
     void resume();
 
     // Need to promptly stop this timer when it is deemed finalizable.
     EAGERLY_FINALIZE();
     DECLARE_TRACE();
 
 private:
     explicit XMLHttpRequestProgressEventThrottle(XMLHttpRequest*);
 
+    // Dispatches a "progress" progress event and usually a readyStateChange
+    // event as well.
+    void dispatchProgressProgressEvent(bool lengthComputable, unsigned long long loaded, unsigned long long total);
+
     // The main purpose of this class is to throttle the "progress"
     // ProgressEvent dispatching. This class represents such a deferred
     // "progress" ProgressEvent.
     class DeferredEvent;
     static const double minimumProgressEventDispatchingIntervalInSeconds;
 
     void fired() override;
     void dispatchDeferredEvent();
 
-    // Non-Oilpan, keep a weak pointer to our XMLHttpRequest object as it is
-    // the one holding us. With Oilpan, a simple strong Member can be used -
-    // this XMLHttpRequestProgressEventThrottle (part) object dies together
-    // with the XMLHttpRequest object.
     Member<XMLHttpRequest> m_target;
 
     // A slot for the deferred "progress" ProgressEvent. When multiple events
     // arrive, only the last one is stored and others are discarded.
     const OwnPtr<DeferredEvent> m_deferred;
+    // True if any "progress" progress event has been dispatched since
+    // |m_target|'s readyState changed.
+    bool m_hasDispatchedProgressProgressEvent;
 };
 
 } // namespace blink
 
 #endif // XMLHttpRequestProgressEventThrottle_h