DevTools: move FileSystemMapping under persistence/ module

third_party/WebKit/LayoutTests/http/tests/inspector/isolated-filesystem-test.js

 var initialize_IsolatedFileSystemTest = function() {
 
 InspectorFrontendHost.isolatedFileSystem = function(name)
 {
     return InspectorTest.TestFileSystem._instances[name];
 }
 
 InspectorTest.TestFileSystem = function(fileSystemPath)
 {
     this.root = new InspectorTest.TestFileSystem.Entry(this, "", true, null);
@@ skipping 43 matching lines @@
     },
 
     reportRemoved: function()
     {
         delete InspectorTest.TestFileSystem._instances[this.fileSystemPath];
         InspectorFrontendHost.events.dispatchEventToListeners(InspectorFrontendHostAPI.Events.FileSystemRemoved, this.fileSystemPath);
     },
 
     addFileMapping: function(urlPrefix, pathPrefix)
     {
-        var fileSystemMapping = new Workspace.FileSystemMapping(Workspace.isolatedFileSystemManager);
+        var fileSystemMapping = new Persistence.FileSystemMapping(Workspace.isolatedFileSystemManager);
         fileSystemMapping.addFileSystem(this.fileSystemPath);
         fileSystemMapping.addFileMapping(this.fileSystemPath, urlPrefix, pathPrefix);
         fileSystemMapping.dispose();
-        Workspace.fileSystemMapping._loadFromSettings();
+        Persistence.fileSystemMapping._loadFromSettings();
     },
 
     /**
      * @param {string} path
      * @param {string} content
      * @param {number} lastModified
      */
     addFile: function(path, content, lastModified)
     {
         var pathTokens = path.split("/");
@@ skipping 181 matching lines @@
     truncate: function(num)
     {
         this._entry._timestamp += this._modificationTimesDelta;
         this._entry.content = this._entry.content.slice(0, num);
         if (this.onwriteend)
             this.onwriteend();
     }
 }
 
 };