[DevTools] Make resource tree model optional

third_party/WebKit/Source/devtools/front_end/sdk/ServiceWorkerCacheModel.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.
 
 /**
  * Invariant: This model can only be constructed on a ServiceWorker target.
  * @constructor
  * @extends {WebInspector.SDKModel}
  */
 WebInspector.ServiceWorkerCacheModel = function(target)
@@ skipping 13 matching lines @@
     CacheAdded: "CacheAdded",
     CacheRemoved: "CacheRemoved"
 }
 
 WebInspector.ServiceWorkerCacheModel.prototype = {
     enable: function()
     {
         if (this._enabled)
             return;
 
-        this.target().resourceTreeModel.addEventListener(WebInspector.ResourceTreeModel.EventTypes.SecurityOriginAdded, this._securityOriginAdded, this);
-        this.target().resourceTreeModel.addEventListener(WebInspector.ResourceTreeModel.EventTypes.SecurityOriginRemoved, this._securityOriginRemoved, this);
-
-        var securityOrigins = this.target().resourceTreeModel.securityOrigins();
-        for (var i = 0; i < securityOrigins.length; ++i)
-            this._addOrigin(securityOrigins[i]);
+        var resourceTreeModel = WebInspector.ResourceTreeModel.fromTarget(this.target());
+        if (resourceTreeModel) {

[dgozman, 2016/07/14 16:29:29]

Require it.

[eostroukhov-old, 2016/07/20 23:46:16]

Done.

+            resourceTreeModel.addEventListener(WebInspector.ResourceTreeModel.EventTypes.SecurityOriginAdded, this._securityOriginAdded, this);
+            resourceTreeModel.addEventListener(WebInspector.ResourceTreeModel.EventTypes.SecurityOriginRemoved, this._securityOriginRemoved, this);
+            var securityOrigins = resourceTreeModel.securityOrigins();
+            for (var i = 0; i < securityOrigins.length; ++i)
+                this._addOrigin(securityOrigins[i]);
+        }
         this._enabled = true;
     },
 
     /**
      * @param {string} origin
      */
     clearForOrigin: function(origin)
     {
         this._removeOrigin(origin);
         this._addOrigin(origin);
     },
 
     refreshCacheNames: function()
     {
         for (var cache of this._caches.values())
             this._cacheRemoved(cache);
         this._caches.clear();
-        var securityOrigins = this.target().resourceTreeModel.securityOrigins();
+        var resourceTreeModel = WebInspector.ResourceTreeModel.fromTarget(this.target());
+        var securityOrigins = resourceTreeModel ? resourceTreeModel.securityOrigins() : [];
         for (var securityOrigin of securityOrigins)
             this._loadCacheNames(securityOrigin);
     },
 
     /**
      * @param {!WebInspector.ServiceWorkerCacheModel.Cache} cache
      */
     deleteCache: function(cache)
     {
         /**
@@ skipping 53 matching lines @@
         for (var cache of this._caches.values())
             caches.push(cache);
         return caches;
     },
 
     dispose: function()
     {
         for (var cache of this._caches.values())
             this._cacheRemoved(cache);
         this._caches.clear();
-        if (this._enabled) {
-            this.target().resourceTreeModel.removeEventListener(WebInspector.ResourceTreeModel.EventTypes.SecurityOriginAdded, this._securityOriginAdded, this);
-            this.target().resourceTreeModel.removeEventListener(WebInspector.ResourceTreeModel.EventTypes.SecurityOriginRemoved, this._securityOriginRemoved, this);
+        var resourceTreeModel = WebInspector.ResourceTreeModel.fromTarget(this.target());
+        if (this._enabled && resourceTreeModel) {
+            resourceTreeModel.removeEventListener(WebInspector.ResourceTreeModel.EventTypes.SecurityOriginAdded, this._securityOriginAdded, this);
+            resourceTreeModel.removeEventListener(WebInspector.ResourceTreeModel.EventTypes.SecurityOriginRemoved, this._securityOriginRemoved, this);
         }
     },
 
     _addOrigin: function(securityOrigin)
     {
         this._loadCacheNames(securityOrigin);
     },
 
     /**
      * @param {string} securityOrigin
@@ skipping 183 matching lines @@
  * @param {!WebInspector.Target} target
  * @return {!WebInspector.ServiceWorkerCacheModel}
  */
 WebInspector.ServiceWorkerCacheModel.fromTarget = function(target)
 {
     if (!target[WebInspector.ServiceWorkerCacheModel._symbol])
         target[WebInspector.ServiceWorkerCacheModel._symbol] = new WebInspector.ServiceWorkerCacheModel(target);
 
     return target[WebInspector.ServiceWorkerCacheModel._symbol];
 }