[DevTools] Support broken UMA metric from M49 frontend.

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 (function(window) {
 
 // DevToolsAPI ----------------------------------------------------------------
 
 /**
  * @constructor
@@ skipping 507 matching lines @@
     },
 
     /**
      * @override
      * @param {string} actionName
      * @param {number} actionCode
      * @param {number} bucketSize
      */
     recordEnumeratedHistogram: function(actionName, actionCode, bucketSize)
     {
+        // Support for M49 frontend.
+        if (actionName === "DevTools.DrawerShown")
+            return;
         DevToolsAPI.sendMessageToEmbedder("recordEnumeratedHistogram", [actionName, actionCode, bucketSize], null);
     },
 
     /**
      * @override
      */
     requestFileSystems: function()
     {
         DevToolsAPI.sendMessageToEmbedder("requestFileSystems", [], null);
     },
@@ skipping 489 matching lines @@
 
 if (!DOMTokenList.prototype.__originalDOMTokenListToggle) {
     DOMTokenList.prototype.__originalDOMTokenListToggle = DOMTokenList.prototype.toggle;
     DOMTokenList.prototype.toggle = function(token, force)
     {
         if (arguments.length === 1)
             force = !this.contains(token);
         return this.__originalDOMTokenListToggle(token, !!force);
     }
 }