[DevTools] Swallow mouse up in inspect mode

third_party/WebKit/Source/web/InspectorOverlay.cpp

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 245 matching lines @@
     OverlayMainFrame()->GetEventHandler().HandleGestureEvent(transformed_event);
   }
   if (WebInputEvent::IsMouseEventType(input_event.GetType())) {
     WebMouseEvent mouse_event =
         TransformWebMouseEvent(frame_impl_->GetFrameView(),
                                static_cast<const WebMouseEvent&>(input_event));
 
     if (mouse_event.GetType() == WebInputEvent::kMouseMove)
       handled = HandleMouseMove(mouse_event);
     else if (mouse_event.GetType() == WebInputEvent::kMouseDown)
-      handled = HandleMousePress();
+      handled = HandleMouseDown();
+    else if (mouse_event.GetType() == WebInputEvent::kMouseUp)
+      handled = HandleMouseUp();
 
     if (handled)
       return true;
 
     if (mouse_event.GetType() == WebInputEvent::kMouseMove) {
       handled = OverlayMainFrame()->GetEventHandler().HandleMouseMoveEvent(
                     mouse_event, TransformWebMouseEventVector(
                                      frame_impl_->GetFrameView(),
                                      std::vector<const WebInputEvent*>())) !=
                 WebInputEventResult::kNotHandled;
@@ skipping 482 matching lines @@
     hovered_node_for_inspect_mode_ = node;
     if (dom_agent_)
       dom_agent_->NodeHighlightedInOverlay(node);
     HighlightNode(node, event_target, *inspect_mode_highlight_config_,
                   (event.GetModifiers() &
                    (WebInputEvent::kControlKey | WebInputEvent::kMetaKey)));
   }
   return true;
 }
 
-bool InspectorOverlay::HandleMousePress() {
+bool InspectorOverlay::HandleMouseDown() {
+  return ShouldSearchForNode();

[pfeldman, 2017/04/14 00:37:39]

As of this moment, don't update hovered_node_for_inspect_mode_.

+}
+
+bool InspectorOverlay::HandleMouseUp() {
   if (!ShouldSearchForNode())
     return false;
 
   if (hovered_node_for_inspect_mode_) {
     Inspect(hovered_node_for_inspect_mode_.Get());
     hovered_node_for_inspect_mode_.Clear();
     return true;
   }
   return false;
 }
@@ skipping 25 matching lines @@
 bool InspectorOverlay::ShouldSearchForNode() {
   return inspect_mode_ != InspectorDOMAgent::kNotSearching;
 }
 
 void InspectorOverlay::Inspect(Node* node) {
   if (dom_agent_)
     dom_agent_->Inspect(node);
 }
 
 }  // namespace blink