Clear the state of scroll and selection onmouseup

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 88231b20507d3c80971eb3deb373786d143eaaad..8e454390acec58bcf09cb63ba81c582c709365cf 100644
--- a/third_party/WebKit/Source/core/input/EventHandler.cpp
+++ b/third_party/WebKit/Source/core/input/EventHandler.cpp
@@ -1003,13 +1003,15 @@ WebInputEventResult EventHandler::HandleMouseReleaseEvent(
 
   scroll_manager_->ClearResizeScrollableArea(false);
 
-  if (event_result == WebInputEventResult::kNotHandled)
-    event_result = mouse_event_manager_->HandleMouseReleaseEvent(mev);
+  WebInputEventResult selection_scroll_event_result =
+      mouse_event_manager_->HandleMouseReleaseEvent(mev);

[dtapuska, 2017/05/08 18:54:07]

What about preventing the paste on middle click result..

https://cs.chromium.org/chromium/src/third_party/WebKit/Source/core/editing/S...

?

   mouse_event_manager_->ClearDragHeuristicState();
 
   mouse_event_manager_->InvalidateClick();
 
-  return EventHandlingUtil::MergeEventResult(click_event_result, event_result);
+  return EventHandlingUtil::MergeEventResult(
+      EventHandlingUtil::MergeEventResult(click_event_result, event_result),
+      selection_scroll_event_result);
 }
 
 static bool TargetIsFrame(Node* target, LocalFrame*& frame) {