[DevTools] Make resource tree model optional

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

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 61 matching lines @@
     PageReloadRequested: "PageReloadRequested",
     WillReloadPage: "WillReloadPage",
     InspectedURLChanged: "InspectedURLChanged",
     SecurityOriginAdded: "SecurityOriginAdded",
     SecurityOriginRemoved: "SecurityOriginRemoved",
     ScreencastFrame: "ScreencastFrame",
     ScreencastVisibilityChanged: "ScreencastVisibilityChanged",
     ColorPicked: "ColorPicked"
 }
 
+/**
+ * @param {!WebInspector.Target} target
+ * @return {?WebInspector.ResourceTreeModel}
+ */
+WebInspector.ResourceTreeModel.fromTarget = function(target) {
+    return /** @type {?WebInspector.ResourceTreeModel} */ (target.model(WebInspector.ResourceTreeModel));
+}
 
 /**
  * @return {!Array.<!WebInspector.ResourceTreeFrame>}
  */
 WebInspector.ResourceTreeModel.frames = function()
 {
     var result = [];
-    for (var target of WebInspector.targetManager.targets())
-        result = result.concat(Object.values(target.resourceTreeModel._frames));
+    for (var target of WebInspector.targetManager.targets()) {
+        var resourceTreeModel = WebInspector.ResourceTreeModel.fromTarget(target);
+        if (resourceTreeModel)
+            result = result.concat(Object.values(resourceTreeModel._frames));
+    }
     return result;
 }
 
 /**
  * @param {string} url
  * @return {?WebInspector.Resource}
  */
 WebInspector.ResourceTreeModel.resourceForURL = function(url)
 {
     for (var target of WebInspector.targetManager.targets()) {
-        var mainFrame = target.resourceTreeModel.mainFrame;
+        var resourceTreeModel = WebInspector.ResourceTreeModel.fromTarget(target);
+        var mainFrame = resourceTreeModel && resourceTreeModel.mainFrame;
         var result = mainFrame ? mainFrame.resourceForURL(url) : null;
         if (result)
             return result;
     }
     return null;
 }
 
 WebInspector.ResourceTreeModel.prototype = {
     _fetchResourceTree: function()
     {
@@ skipping 407 matching lines @@
 
     /**
      * @type {!Object.<string, !WebInspector.Resource>}
      */
     this._resourcesMap = {};
 
     if (this._parentFrame)
         this._parentFrame._childFrames.push(this);
 }
 
+
+/**
+ * @param {!WebInspector.ExecutionContext|!WebInspector.CSSStyleSheetHeader|!WebInspector.Resource} object
+ * @return {?WebInspector.ResourceTreeFrame}
+ */
+WebInspector.ResourceTreeFrame._fromObject = function(object)
+{
+    var resourceTreeModel = WebInspector.ResourceTreeModel.fromTarget(object.target());
+    var frameId = object.frameId;
+    if (!resourceTreeModel || !frameId)
+        return null;
+    return resourceTreeModel.frameForId(frameId);
+}
+
 /**
  * @param {!WebInspector.Script} script
  * @return {?WebInspector.ResourceTreeFrame}
  */
 WebInspector.ResourceTreeFrame.fromScript = function(script)
 {
     var executionContext = script.executionContext();
-    if (!executionContext || !executionContext.frameId)
+    if (!executionContext)
         return null;
-    return script.target().resourceTreeModel.frameForId(executionContext.frameId);
+    return WebInspector.ResourceTreeFrame._fromObject(executionContext);
 }
 
 /**
  * @param {!WebInspector.CSSStyleSheetHeader} header
  * @return {?WebInspector.ResourceTreeFrame}
  */
 WebInspector.ResourceTreeFrame.fromStyleSheet = function(header)
 {
-    return header.target().resourceTreeModel.frameForId(header.frameId);
+    return WebInspector.ResourceTreeFrame._fromObject(header);
 }
 
 /**
  * @param {!WebInspector.Resource} resource
  * @return {?WebInspector.ResourceTreeFrame}
  */
 WebInspector.ResourceTreeFrame.fromResource = function(resource)
 {
-    return resource.target().resourceTreeModel.frameForId(resource.frameId);
+    return WebInspector.ResourceTreeFrame._fromObject(resource);
 }
 
 WebInspector.ResourceTreeFrame.prototype = {
     /**
      * @return {!WebInspector.Target}
      */
     target: function()
     {
         return this._model.target();
     },
@@ skipping 359 matching lines @@
     },
 
     /**
      * @override
      */
     interstitialHidden: function()
     {
         // Frontend is not interested in interstitials.
     }
 }