DevTools: do not discard soft context menu on glass pane mouseup unconditionally.

Source/devtools/front_end/ui/SoftContextMenu.js

Index: Source/devtools/front_end/ui/SoftContextMenu.js
diff --git a/Source/devtools/front_end/ui/SoftContextMenu.js b/Source/devtools/front_end/ui/SoftContextMenu.js
index e4f8777d082710bf1faadda7b3f2ec609c26a6ef..ace88f84fda3a5c38e97a988eec57ed7f40e3816 100644
--- a/Source/devtools/front_end/ui/SoftContextMenu.js
+++ b/Source/devtools/front_end/ui/SoftContextMenu.js
@@ -329,6 +329,8 @@ WebInspector.SoftContextMenu.prototype = {
         // Return if this is simple 'click', since dispatched on glass pane, can't use 'click' event.
         if (new Date().getTime() - this._time < 300)
             return;
+        if (event.target === this.element)
+            return;
         this._discardMenu(true, event);
         event.consume();
     },