Remove EventHandler::m_didStartDrag.

Source/core/page/EventHandler.h

Index: Source/core/page/EventHandler.h
diff --git a/Source/core/page/EventHandler.h b/Source/core/page/EventHandler.h
index eb4c70047666085d572c3507adc13e59c9c8c5cf..928dedc7dc10f851135704ece87d26a3d28b7917 100644
--- a/Source/core/page/EventHandler.h
+++ b/Source/core/page/EventHandler.h
@@ -80,7 +80,7 @@ class WheelEvent;
 class Widget;
 
 enum AppendTrailingWhitespace { ShouldAppendTrailingWhitespace, DontAppendTrailingWhitespace };
-enum CheckDragHysteresis { ShouldCheckDragHysteresis, DontCheckDragHysteresis };
+enum class DragInitiator;
 
 class EventHandler : public NoBaseWillBeGarbageCollectedFinalized<EventHandler> {
     WTF_MAKE_NONCOPYABLE(EventHandler);
@@ -276,7 +276,7 @@ private:
 
     void clearDragDataTransfer();
 
-    bool handleDrag(const MouseEventWithHitTestResults&, CheckDragHysteresis);
+    bool handleDrag(const MouseEventWithHitTestResults&, DragInitiator);
     bool tryStartDrag(const MouseEventWithHitTestResults&);
     void clearDragState();
 
@@ -395,7 +395,6 @@ private:
     RefPtrWillBeMember<Scrollbar> m_scrollbarHandlingScrollGesture;
 
     double m_maxMouseMovedDuration;
-    bool m_didStartDrag;
 
     bool m_longTapShouldInvokeContextMenu;