Reset drag state variables on mouse up

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 04b488f2cf5755fc2d017c11b7f5758beeeb7fc9..864f214974333ffe74678e4e1a98886a0f6a7b53 100644
--- a/third_party/WebKit/Source/core/input/EventHandler.cpp
+++ b/third_party/WebKit/Source/core/input/EventHandler.cpp
@@ -436,13 +436,6 @@ WebInputEventResult EventHandler::handleMouseReleaseEvent(const MouseEventWithHi
     if (controller && controller->autoscrollInProgress())
         m_scrollManager.stopAutoscroll();
 
-    // Used to prevent mouseMoveEvent from initiating a drag before
-    // the mouse is pressed again.
-    m_mousePressed = false;
-    m_capturesDragging = false;
-    m_mouseDownMayStartDrag = false;
-    m_mouseDownMayStartAutoscroll = false;
-
     return selectionController().handleMouseReleaseEvent(event, m_dragStartPos) ? WebInputEventResult::HandledSystem : WebInputEventResult::NotHandled;
 }
 
@@ -1212,6 +1205,7 @@ WebInputEventResult EventHandler::handleMouseReleaseEvent(const PlatformMouseEve
 
     if (eventResult == WebInputEventResult::NotHandled)
         eventResult = handleMouseReleaseEvent(mev);
+    clearDragHeuristicState();
 
     invalidateClick();
 
@@ -1389,6 +1383,16 @@ WebInputEventResult EventHandler::performDragAndDrop(const PlatformMouseEvent& e
     return result;
 }
 
+void EventHandler::clearDragHeuristicState()
+{
+    // Used to prevent mouseMoveEvent from initiating a drag before
+    // the mouse is pressed again.
+    m_mousePressed = false;
+    m_capturesDragging = false;
+    m_mouseDownMayStartDrag = false;
+    m_mouseDownMayStartAutoscroll = false;
+}
+
 void EventHandler::clearDragState()
 {
     m_scrollManager.stopAutoscroll();
@@ -1874,6 +1878,7 @@ WebInputEventResult EventHandler::handleGestureTap(const GestureEventWithHitTest
 
     if (mouseUpEventResult == WebInputEventResult::NotHandled)
         mouseUpEventResult = handleMouseReleaseEvent(MouseEventWithHitTestResults(fakeMouseUp, currentHitTest));
+    clearDragHeuristicState();
 
     WebInputEventResult eventResult = mergeEventResult(mergeEventResult(mouseDownEventResult, mouseUpEventResult), clickEventResult);
     if (eventResult == WebInputEventResult::NotHandled && tappedNode && m_frame->page()) {