[DevTools] Add 200ms timeout to menu on mousedown behavior.

third_party/WebKit/Source/devtools/front_end/ui/Toolbar.js

Index: third_party/WebKit/Source/devtools/front_end/ui/Toolbar.js
diff --git a/third_party/WebKit/Source/devtools/front_end/ui/Toolbar.js b/third_party/WebKit/Source/devtools/front_end/ui/Toolbar.js
index cfc5efd13db88e8f10692ce1cf6437ecc63b37f7..70c374e8dcbc3ce3142f65ecb1f339cf698cd52d 100644
--- a/third_party/WebKit/Source/devtools/front_end/ui/Toolbar.js
+++ b/third_party/WebKit/Source/devtools/front_end/ui/Toolbar.js
@@ -644,6 +644,16 @@ WebInspector.ToolbarMenuButton.prototype = {
             return;
         }
 
+        if (!this._triggerTimeout)
+            this._triggerTimeout = setTimeout(this._trigger.bind(this, event), 200);
+    },
+
+    /**
+     * @param {!Event} event
+     */
+    _trigger: function(event)
+    {
+        delete this._triggerTimeout;

[PhistucK, 2016/03/16 18:04:48]

As far as I know, delete foo; is discouraged because it "rebuilds the world" (so
optimizations may have to be re-compiled?) and hurts performance.

Perhaps just this._triggerTimeout = 0;?

[pfeldman, 2016/03/16 19:33:31]

This code path will never be optimized in the first place and delete property is
something we carry from the WebKit times.

         var contextMenu = new WebInspector.ContextMenu(event,
             this._useSoftMenu,
             this.element.totalOffsetLeft(),
@@ -658,6 +668,10 @@ WebInspector.ToolbarMenuButton.prototype = {
      */
     _clicked: function(event)
     {
+        if (!this._triggerTimeout)
+            return;
+        clearTimeout(this._triggerTimeout);
+        this._trigger(event);
     },
 
     __proto__: WebInspector.ToolbarButton.prototype