1270788 - It's possible to accidentally end up dragging several nodes in markup at once WITH E10S DISABLED

Status: NEW

(DevTools :: Inspector, defect, P3)

Description

[Patrick Brosset <:pbro>]

+++ This bug was initially created as a clone of Bug #1232806 +++

>>>   My Info:   Win7_64, Nightly 45, 32bit, ID 20151215030221
STR:
1. Open this "data:" url
>   data:text/html,<a><b><div></div></b></a>
2. Open devtools -> inspector, expand the tree in markup-view.
3. Move mouse pointer over <div> string in markup, press left mouse button to start dragging, then
   move mouse over the center of content area (on the page) and release left mouse button
4. Repeat Step 3 with <b> string in markup
5. Repeat Step 3 with <a> string in markup

Result:       
 After Step 5 you're dragging 3 items at once. Pressing Escape cancels only the last node

Expectations: 
 After Step 3 drag-n-drop operation should be canceled correctly