Skip updating nodeUnderMouse to clickTarget.

third_party/WebKit/Source/core/input/EventHandler.cpp

Index: third_party/WebKit/Source/core/input/EventHandler.cpp
diff --git a/third_party/WebKit/Source/core/input/EventHandler.cpp b/third_party/WebKit/Source/core/input/EventHandler.cpp
index fd18e7773acb663f5283364ed8acf871ec2c1f9e..05d04fa5da29ccae25029bbd7e6dd4a5f2833f99 100644
--- a/third_party/WebKit/Source/core/input/EventHandler.cpp
+++ b/third_party/WebKit/Source/core/input/EventHandler.cpp
@@ -1270,8 +1270,16 @@ bool EventHandler::handleMouseReleaseEvent(const PlatformMouseEvent& mouseEvent)
         // Both m_clickNode and mev.innerNode() don't need to be updated
         // because commonAncestor() will exit early if their documents are different.
         m_clickNode->updateDistribution();
-        if (Node* clickTargetNode = mev.innerNode()->commonAncestor(*m_clickNode, parentForClickEvent))
-            swallowClickEvent = !dispatchMouseEvent(EventTypeNames::click, clickTargetNode, m_clickCount, mouseEvent);
+        if (Node* clickTargetNode = mev.innerNode()->commonAncestor(
+            *m_clickNode, parentForClickEvent)) {
+
+            // Dispatch mouseup directly w/o calling updateMouseEventTargetNode
+            // because the mouseup dispatch above has already updated it
+            // correctly. Moreover, clickTargetNode is different from
+            // mev.innerNode at drag-release.
+            clickTargetNode->dispatchMouseEvent(mouseEvent,
+                EventTypeNames::click, m_clickCount);
+        }
     }
 
     if (m_resizeScrollableArea) {