Make sure that selection is cleared after tapping.

Source/core/page/EventHandler.cpp

Index: Source/core/page/EventHandler.cpp
diff --git a/Source/core/page/EventHandler.cpp b/Source/core/page/EventHandler.cpp
index 824ae35d027e5e07ee0809738e5ffff2216c2d3b..39144e39706309183233525648a83c58b10f6e8a 100644
--- a/Source/core/page/EventHandler.cpp
+++ b/Source/core/page/EventHandler.cpp
@@ -2252,8 +2252,11 @@ bool EventHandler::handleGestureTap(const GestureEventWithHitTestResults& target
     bool swallowMouseDownEvent = !dispatchMouseEvent(EventTypeNames::mousedown, currentHitTest.innerNode(), gestureEvent.tapCount(), fakeMouseDown, true);
     if (!swallowMouseDownEvent)
         swallowMouseDownEvent = handleMouseFocus(MouseEventWithHitTestResults(fakeMouseDown, currentHitTest));
-    if (!swallowMouseDownEvent)
+    if (!swallowMouseDownEvent) {
         swallowMouseDownEvent = handleMousePressEvent(MouseEventWithHitTestResults(fakeMouseDown, currentHitTest));
+        // m_selectionInitiationState is initialized after dispatching mousedown event.
+        m_selectionInitiationState = HaveNotStartedSelection;
+    }
 
     // FIXME: Use a hit-test cache to avoid unnecessary hit tests. http://crbug.com/398920
     if (currentHitTest.innerNode())