DevTools: move functionality away from ElementsPanel for better DOM tree control reuse.

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 711d4837cc2c65ba57a7fa5ad03ae442eca3048c..6a000d933b869656abe8e788b9e3e1b7ae64936d 100644
--- a/third_party/WebKit/Source/devtools/front_end/ui/Toolbar.js
+++ b/third_party/WebKit/Source/devtools/front_end/ui/Toolbar.js
@@ -945,7 +945,7 @@ WebInspector.ExtensibleToolbar.prototype = {
             if (extensions[i].descriptor()["location"] === location)
                 promises.push(resolveItem(extensions[i]));
         }
-        this._promise = Promise.all(promises).then(appendItemsInOrder.bind(this));
+        Promise.all(promises).then(appendItemsInOrder.bind(this));
 
         /**
          * @param {!Runtime.Extension} extension
@@ -985,13 +985,5 @@ WebInspector.ExtensibleToolbar.prototype = {
         }
     },
 
-    /**
-     * @return {!Promise}
-     */
-    onLoad: function()
-    {
-        return this._promise;
-    },
-
     __proto__: WebInspector.Toolbar.prototype
 }