DevTools: reformat front-end code to match chromium style.

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

Index: third_party/WebKit/Source/devtools/front_end/sources/TabbedEditorContainer.js
diff --git a/third_party/WebKit/Source/devtools/front_end/sources/TabbedEditorContainer.js b/third_party/WebKit/Source/devtools/front_end/sources/TabbedEditorContainer.js
index 872798171c43677ae40110f32a0de801714cadc2..1f41d7c6d2ef12c86e693043da1d0118511c3a97 100644
--- a/third_party/WebKit/Source/devtools/front_end/sources/TabbedEditorContainer.js
+++ b/third_party/WebKit/Source/devtools/front_end/sources/TabbedEditorContainer.js
@@ -25,30 +25,30 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
-
 /**
  * @interface
  */
-WebInspector.TabbedEditorContainerDelegate = function() { };
+WebInspector.TabbedEditorContainerDelegate = function() {};
 
 WebInspector.TabbedEditorContainerDelegate.prototype = {
-    /**
-     * @param {!WebInspector.UISourceCode} uiSourceCode
-     * @return {!WebInspector.Widget}
-     */
-    viewForFile: function(uiSourceCode) { },
+  /**
+   * @param {!WebInspector.UISourceCode} uiSourceCode
+   * @return {!WebInspector.Widget}
+   */
+  viewForFile: function(uiSourceCode) {},
 };
 
 /**
- * @constructor
- * @extends {WebInspector.Object}
- * @param {!WebInspector.TabbedEditorContainerDelegate} delegate
- * @param {!WebInspector.Setting} setting
- * @param {string} placeholderText
+ * @unrestricted
  */
-WebInspector.TabbedEditorContainer = function(delegate, setting, placeholderText)
-{
-    WebInspector.Object.call(this);
+WebInspector.TabbedEditorContainer = class extends WebInspector.Object {
+  /**
+   * @param {!WebInspector.TabbedEditorContainerDelegate} delegate
+   * @param {!WebInspector.Setting} setting
+   * @param {string} placeholderText
+   */
+  constructor(delegate, setting, placeholderText) {
+    super();
     this._delegate = delegate;
 
     this._tabbedPane = new WebInspector.TabbedPane();
@@ -61,799 +61,763 @@ WebInspector.TabbedEditorContainer = function(delegate, setting, placeholderText
     this._tabbedPane.addEventListener(WebInspector.TabbedPane.Events.TabClosed, this._tabClosed, this);
     this._tabbedPane.addEventListener(WebInspector.TabbedPane.Events.TabSelected, this._tabSelected, this);
 
-    WebInspector.persistence.addEventListener(WebInspector.Persistence.Events.BindingCreated, this._onBindingCreated, this);
-    WebInspector.persistence.addEventListener(WebInspector.Persistence.Events.BindingRemoved, this._onBindingRemoved, this);
+    WebInspector.persistence.addEventListener(
+        WebInspector.Persistence.Events.BindingCreated, this._onBindingCreated, this);
+    WebInspector.persistence.addEventListener(
+        WebInspector.Persistence.Events.BindingRemoved, this._onBindingRemoved, this);
 
     this._tabIds = new Map();
     this._files = {};
 
     this._previouslyViewedFilesSetting = setting;
     this._history = WebInspector.TabbedEditorContainer.History.fromObject(this._previouslyViewedFilesSetting.get());
-};
-
-/** @enum {symbol} */
-WebInspector.TabbedEditorContainer.Events = {
-    EditorSelected: Symbol("EditorSelected"),
-    EditorClosed: Symbol("EditorClosed")
-};
-
-WebInspector.TabbedEditorContainer._tabId = 0;
-
-WebInspector.TabbedEditorContainer.maximalPreviouslyViewedFilesCount = 30;
-
-WebInspector.TabbedEditorContainer.prototype = {
-    /**
-     * @param {!WebInspector.Event} event
-     */
-    _onBindingCreated: function(event)
-    {
-        var binding = /** @type {!WebInspector.PersistenceBinding} */(event.data);
-        var networkTabId = this._tabIds.get(binding.network);
-        var fileSystemTabId = this._tabIds.get(binding.fileSystem);
-
-        if (networkTabId)
-            this._tabbedPane.changeTabTitle(networkTabId, this._titleForFile(binding.fileSystem), this._tooltipForFile(binding.fileSystem));
-        if (!fileSystemTabId)
-            return;
-
-        var wasSelectedInFileSystem = this._currentFile === binding.fileSystem;
-        var currentSelectionRange = this._history.selectionRange(binding.fileSystem.url());
-        var currentScrollLineNumber = this._history.scrollLineNumber(binding.fileSystem.url());
-
-        var tabIndex = this._tabbedPane.tabIndex(fileSystemTabId);
-        var tabsToClose = [fileSystemTabId];
-        if (networkTabId)
-            tabsToClose.push(networkTabId);
-        this._closeTabs(tabsToClose, true);
-        networkTabId = this._appendFileTab(binding.network, false, tabIndex);
-        this._updateHistory();
-
-        if (wasSelectedInFileSystem)
-            this._tabbedPane.selectTab(networkTabId, false);
-
-        var networkTabView = /** @type {!WebInspector.Widget} */(this._tabbedPane.tabView(networkTabId));
-        this._restoreEditorProperties(networkTabView, currentSelectionRange, currentScrollLineNumber);
-    },
-
-    /**
-     * @param {!WebInspector.Event} event
-     */
-    _onBindingRemoved: function(event)
-    {
-        var binding = /** @type {!WebInspector.PersistenceBinding} */(event.data);
-        var networkTabId = this._tabIds.get(binding.network);
-        if (!networkTabId)
-            return;
-        var tabIndex = this._tabbedPane.tabIndex(networkTabId);
-        var wasSelected = this._currentFile === binding.network;
-        var fileSystemTabId = this._appendFileTab(binding.fileSystem, false, tabIndex);
-        this._updateHistory();
-
-        if (wasSelected)
-            this._tabbedPane.selectTab(fileSystemTabId, false);
-
-        var fileSystemTabView = /** @type {!WebInspector.Widget} */(this._tabbedPane.tabView(fileSystemTabId));
-        var savedSelectionRange = this._history.selectionRange(binding.network.url());
-        var savedScrollLineNumber = this._history.scrollLineNumber(binding.network.url());
-        this._restoreEditorProperties(fileSystemTabView, savedSelectionRange, savedScrollLineNumber);
-    },
-
-    /**
-     * @return {!WebInspector.Widget}
-     */
-    get view()
-    {
-        return this._tabbedPane;
-    },
-
-    /**
-     * @type {!WebInspector.Widget}
-     */
-    get visibleView()
-    {
-        return this._tabbedPane.visibleView;
-    },
-
-    /**
-     * @return {!Array.<!WebInspector.Widget>}
-     */
-    fileViews: function()
-    {
-        return /** @type {!Array.<!WebInspector.Widget>} */ (this._tabbedPane.tabViews());
-    },
-
-    /**
-     * @return {!WebInspector.Toolbar}
-     */
-    leftToolbar: function()
-    {
-        return this._tabbedPane.leftToolbar();
-    },
-
-    /**
-     * @return {!WebInspector.Toolbar}
-     */
-    rightToolbar: function()
-    {
-        return this._tabbedPane.rightToolbar();
-    },
-
-    /**
-     * @param {!Element} parentElement
-     */
-    show: function(parentElement)
-    {
-        this._tabbedPane.show(parentElement);
-    },
-
-    /**
-     * @param {!WebInspector.UISourceCode} uiSourceCode
-     */
-    showFile: function(uiSourceCode)
-    {
-        this._innerShowFile(uiSourceCode, true);
-    },
-
-    /**
-     * @param {!WebInspector.UISourceCode} uiSourceCode
-     */
-    closeFile: function(uiSourceCode)
-    {
-        var tabId = this._tabIds.get(uiSourceCode);
-        if (!tabId)
-            return;
-        this._closeTabs([tabId]);
-    },
-
-    closeAllFiles: function()
-    {
-        this._closeTabs(this._tabbedPane.allTabs());
-    },
-
-    /**
-     * @return {!Array.<!WebInspector.UISourceCode>}
-     */
-    historyUISourceCodes: function()
-    {
-        // FIXME: there should be a way to fetch UISourceCode for its uri.
-        var uriToUISourceCode = {};
-        for (var id in this._files) {
-            var uiSourceCode = this._files[id];
-            uriToUISourceCode[uiSourceCode.url()] = uiSourceCode;
-        }
-
-        var result = [];
-        var uris = this._history._urls();
-        for (var i = 0; i < uris.length; ++i) {
-            var uiSourceCode = uriToUISourceCode[uris[i]];
-            if (uiSourceCode)
-                result.push(uiSourceCode);
-        }
-        return result;
-    },
-
-    _addViewListeners: function()
-    {
-        if (!this._currentView || !this._currentView.textEditor)
-            return;
-        this._currentView.textEditor.addEventListener(WebInspector.SourcesTextEditor.Events.ScrollChanged, this._scrollChanged, this);
-        this._currentView.textEditor.addEventListener(WebInspector.SourcesTextEditor.Events.SelectionChanged, this._selectionChanged, this);
-    },
-
-    _removeViewListeners: function()
-    {
-        if (!this._currentView || !this._currentView.textEditor)
-            return;
-        this._currentView.textEditor.removeEventListener(WebInspector.SourcesTextEditor.Events.ScrollChanged, this._scrollChanged, this);
-        this._currentView.textEditor.removeEventListener(WebInspector.SourcesTextEditor.Events.SelectionChanged, this._selectionChanged, this);
-    },
-
-    /**
-     * @param {!WebInspector.Event} event
-     */
-    _scrollChanged: function(event)
-    {
-        if (this._scrollTimer)
-            clearTimeout(this._scrollTimer);
-        var lineNumber = /** @type {number} */ (event.data);
-        this._scrollTimer = setTimeout(saveHistory.bind(this), 100);
-        this._history.updateScrollLineNumber(this._currentFile.url(), lineNumber);
-
-        /**
-         * @this {WebInspector.TabbedEditorContainer}
-         */
-        function saveHistory()
-        {
-            this._history.save(this._previouslyViewedFilesSetting);
-        }
-    },
+  }
+
+  /**
+   * @param {!WebInspector.Event} event
+   */
+  _onBindingCreated(event) {
+    var binding = /** @type {!WebInspector.PersistenceBinding} */ (event.data);
+    var networkTabId = this._tabIds.get(binding.network);
+    var fileSystemTabId = this._tabIds.get(binding.fileSystem);
+
+    if (networkTabId)
+      this._tabbedPane.changeTabTitle(
+          networkTabId, this._titleForFile(binding.fileSystem), this._tooltipForFile(binding.fileSystem));
+    if (!fileSystemTabId)
+      return;
+
+    var wasSelectedInFileSystem = this._currentFile === binding.fileSystem;
+    var currentSelectionRange = this._history.selectionRange(binding.fileSystem.url());
+    var currentScrollLineNumber = this._history.scrollLineNumber(binding.fileSystem.url());
+
+    var tabIndex = this._tabbedPane.tabIndex(fileSystemTabId);
+    var tabsToClose = [fileSystemTabId];
+    if (networkTabId)
+      tabsToClose.push(networkTabId);
+    this._closeTabs(tabsToClose, true);
+    networkTabId = this._appendFileTab(binding.network, false, tabIndex);
+    this._updateHistory();
+
+    if (wasSelectedInFileSystem)
+      this._tabbedPane.selectTab(networkTabId, false);
+
+    var networkTabView = /** @type {!WebInspector.Widget} */ (this._tabbedPane.tabView(networkTabId));
+    this._restoreEditorProperties(networkTabView, currentSelectionRange, currentScrollLineNumber);
+  }
+
+  /**
+   * @param {!WebInspector.Event} event
+   */
+  _onBindingRemoved(event) {
+    var binding = /** @type {!WebInspector.PersistenceBinding} */ (event.data);
+    var networkTabId = this._tabIds.get(binding.network);
+    if (!networkTabId)
+      return;
+    var tabIndex = this._tabbedPane.tabIndex(networkTabId);
+    var wasSelected = this._currentFile === binding.network;
+    var fileSystemTabId = this._appendFileTab(binding.fileSystem, false, tabIndex);
+    this._updateHistory();
+
+    if (wasSelected)
+      this._tabbedPane.selectTab(fileSystemTabId, false);
+
+    var fileSystemTabView = /** @type {!WebInspector.Widget} */ (this._tabbedPane.tabView(fileSystemTabId));
+    var savedSelectionRange = this._history.selectionRange(binding.network.url());
+    var savedScrollLineNumber = this._history.scrollLineNumber(binding.network.url());
+    this._restoreEditorProperties(fileSystemTabView, savedSelectionRange, savedScrollLineNumber);
+  }
+
+  /**
+   * @return {!WebInspector.Widget}
+   */
+  get view() {
+    return this._tabbedPane;
+  }
+
+  /**
+   * @return {?WebInspector.Widget}
+   */
+  get visibleView() {
+    return this._tabbedPane.visibleView;
+  }
+
+  /**
+   * @return {!Array.<!WebInspector.Widget>}
+   */
+  fileViews() {
+    return /** @type {!Array.<!WebInspector.Widget>} */ (this._tabbedPane.tabViews());
+  }
+
+  /**
+   * @return {!WebInspector.Toolbar}
+   */
+  leftToolbar() {
+    return this._tabbedPane.leftToolbar();
+  }
+
+  /**
+   * @return {!WebInspector.Toolbar}
+   */
+  rightToolbar() {
+    return this._tabbedPane.rightToolbar();
+  }
+
+  /**
+   * @param {!Element} parentElement
+   */
+  show(parentElement) {
+    this._tabbedPane.show(parentElement);
+  }
+
+  /**
+   * @param {!WebInspector.UISourceCode} uiSourceCode
+   */
+  showFile(uiSourceCode) {
+    this._innerShowFile(uiSourceCode, true);
+  }
+
+  /**
+   * @param {!WebInspector.UISourceCode} uiSourceCode
+   */
+  closeFile(uiSourceCode) {
+    var tabId = this._tabIds.get(uiSourceCode);
+    if (!tabId)
+      return;
+    this._closeTabs([tabId]);
+  }
+
+  closeAllFiles() {
+    this._closeTabs(this._tabbedPane.allTabs());
+  }
+
+  /**
+   * @return {!Array.<!WebInspector.UISourceCode>}
+   */
+  historyUISourceCodes() {
+    // FIXME: there should be a way to fetch UISourceCode for its uri.
+    var uriToUISourceCode = {};
+    for (var id in this._files) {
+      var uiSourceCode = this._files[id];
+      uriToUISourceCode[uiSourceCode.url()] = uiSourceCode;
+    }
 
-    /**
-     * @param {!WebInspector.Event} event
-     */
-    _selectionChanged: function(event)
-    {
-        var range = /** @type {!WebInspector.TextRange} */ (event.data);
-        this._history.updateSelectionRange(this._currentFile.url(), range);
-        this._history.save(this._previouslyViewedFilesSetting);
-    },
+    var result = [];
+    var uris = this._history._urls();
+    for (var i = 0; i < uris.length; ++i) {
+      var uiSourceCode = uriToUISourceCode[uris[i]];
+      if (uiSourceCode)
+        result.push(uiSourceCode);
+    }
+    return result;
+  }
+
+  _addViewListeners() {
+    if (!this._currentView || !this._currentView.textEditor)
+      return;
+    this._currentView.textEditor.addEventListener(
+        WebInspector.SourcesTextEditor.Events.ScrollChanged, this._scrollChanged, this);
+    this._currentView.textEditor.addEventListener(
+        WebInspector.SourcesTextEditor.Events.SelectionChanged, this._selectionChanged, this);
+  }
+
+  _removeViewListeners() {
+    if (!this._currentView || !this._currentView.textEditor)
+      return;
+    this._currentView.textEditor.removeEventListener(
+        WebInspector.SourcesTextEditor.Events.ScrollChanged, this._scrollChanged, this);
+    this._currentView.textEditor.removeEventListener(
+        WebInspector.SourcesTextEditor.Events.SelectionChanged, this._selectionChanged, this);
+  }
+
+  /**
+   * @param {!WebInspector.Event} event
+   */
+  _scrollChanged(event) {
+    if (this._scrollTimer)
+      clearTimeout(this._scrollTimer);
+    var lineNumber = /** @type {number} */ (event.data);
+    this._scrollTimer = setTimeout(saveHistory.bind(this), 100);
+    this._history.updateScrollLineNumber(this._currentFile.url(), lineNumber);
+
+    /**
+     * @this {WebInspector.TabbedEditorContainer}
+     */
+    function saveHistory() {
+      this._history.save(this._previouslyViewedFilesSetting);
+    }
+  }
+
+  /**
+   * @param {!WebInspector.Event} event
+   */
+  _selectionChanged(event) {
+    var range = /** @type {!WebInspector.TextRange} */ (event.data);
+    this._history.updateSelectionRange(this._currentFile.url(), range);
+    this._history.save(this._previouslyViewedFilesSetting);
+  }
+
+  /**
+   * @param {!WebInspector.UISourceCode} uiSourceCode
+   * @param {boolean=} userGesture
+   */
+  _innerShowFile(uiSourceCode, userGesture) {
+    var binding = WebInspector.persistence.binding(uiSourceCode);
+    uiSourceCode = binding ? binding.network : uiSourceCode;
+    if (this._currentFile === uiSourceCode)
+      return;
+
+    this._removeViewListeners();
+    this._currentFile = uiSourceCode;
+
+    var tabId = this._tabIds.get(uiSourceCode) || this._appendFileTab(uiSourceCode, userGesture);
+
+    this._tabbedPane.selectTab(tabId, userGesture);
+    if (userGesture)
+      this._editorSelectedByUserAction();
+
+    var previousView = this._currentView;
+    this._currentView = this.visibleView;
+    this._addViewListeners();
+
+    var eventData = {
+      currentFile: this._currentFile,
+      currentView: this._currentView,
+      previousView: previousView,
+      userGesture: userGesture
+    };
+    this.dispatchEventToListeners(WebInspector.TabbedEditorContainer.Events.EditorSelected, eventData);
+  }
+
+  /**
+   * @param {!WebInspector.UISourceCode} uiSourceCode
+   * @return {string}
+   */
+  _titleForFile(uiSourceCode) {
+    var binding = WebInspector.persistence.binding(uiSourceCode);
+    var titleUISourceCode = binding ? binding.fileSystem : uiSourceCode;
+    var maxDisplayNameLength = 30;
+    var title = titleUISourceCode.displayName(true).trimMiddle(maxDisplayNameLength);
+    if (uiSourceCode.isDirty() || WebInspector.persistence.hasUnsavedCommittedChanges(uiSourceCode))
+      title += '*';
+    return title;
+  }
+
+  /**
+   * @param {string} id
+   * @param {string} nextTabId
+   */
+  _maybeCloseTab(id, nextTabId) {
+    var uiSourceCode = this._files[id];
+    var shouldPrompt = uiSourceCode.isDirty() && uiSourceCode.project().canSetFileContent();
+    // FIXME: this should be replaced with common Save/Discard/Cancel dialog.
+    if (!shouldPrompt ||
+        confirm(WebInspector.UIString('Are you sure you want to close unsaved file: %s?', uiSourceCode.name()))) {
+      uiSourceCode.resetWorkingCopy();
+      var previousView = this._currentView;
+      if (nextTabId)
+        this._tabbedPane.selectTab(nextTabId, true);
+      this._tabbedPane.closeTab(id, true);
+      return true;
+    }
+    return false;
+  }
+
+  /**
+   * @param {!Array.<string>} ids
+   * @param {boolean=} forceCloseDirtyTabs
+   */
+  _closeTabs(ids, forceCloseDirtyTabs) {
+    var dirtyTabs = [];
+    var cleanTabs = [];
+    for (var i = 0; i < ids.length; ++i) {
+      var id = ids[i];
+      var uiSourceCode = this._files[id];
+      if (!forceCloseDirtyTabs && uiSourceCode.isDirty())
+        dirtyTabs.push(id);
+      else
+        cleanTabs.push(id);
+    }
+    if (dirtyTabs.length)
+      this._tabbedPane.selectTab(dirtyTabs[0], true);
+    this._tabbedPane.closeTabs(cleanTabs, true);
+    for (var i = 0; i < dirtyTabs.length; ++i) {
+      var nextTabId = i + 1 < dirtyTabs.length ? dirtyTabs[i + 1] : null;
+      if (!this._maybeCloseTab(dirtyTabs[i], nextTabId))
+        break;
+    }
+  }
+
+  /**
+   * @param {string} tabId
+   * @param {!WebInspector.ContextMenu} contextMenu
+   */
+  _onContextMenu(tabId, contextMenu) {
+    var uiSourceCode = this._files[tabId];
+    if (uiSourceCode)
+      contextMenu.appendApplicableItems(uiSourceCode);
+  }
+
+  /**
+   * @param {!WebInspector.UISourceCode} uiSourceCode
+   */
+  addUISourceCode(uiSourceCode) {
+    var uri = uiSourceCode.url();
+    var index = this._history.index(uri);
+    if (index === -1)
+      return;
+
+    if (!this._tabIds.has(uiSourceCode))
+      this._appendFileTab(uiSourceCode, false);
+
+    // Select tab if this file was the last to be shown.
+    if (!index) {
+      this._innerShowFile(uiSourceCode, false);
+      return;
+    }
 
-    /**
-     * @param {!WebInspector.UISourceCode} uiSourceCode
-     * @param {boolean=} userGesture
-     */
-    _innerShowFile: function(uiSourceCode, userGesture)
-    {
-        var binding = WebInspector.persistence.binding(uiSourceCode);
-        uiSourceCode = binding ? binding.network : uiSourceCode;
-        if (this._currentFile === uiSourceCode)
-            return;
-
-        this._removeViewListeners();
-        this._currentFile = uiSourceCode;
-
-        var tabId = this._tabIds.get(uiSourceCode) || this._appendFileTab(uiSourceCode, userGesture);
-
-        this._tabbedPane.selectTab(tabId, userGesture);
-        if (userGesture)
-            this._editorSelectedByUserAction();
-
-        var previousView = this._currentView;
-        this._currentView = this.visibleView;
-        this._addViewListeners();
-
-        var eventData = {
-            currentFile: this._currentFile,
-            currentView: this._currentView,
-            previousView: previousView,
-            userGesture: userGesture
-        };
-        this.dispatchEventToListeners(WebInspector.TabbedEditorContainer.Events.EditorSelected, eventData);
-    },
+    if (!this._currentFile)
+      return;
+    var currentProjectType = this._currentFile.project().type();
+    var addedProjectType = uiSourceCode.project().type();
+    var snippetsProjectType = WebInspector.projectTypes.Snippets;
+    if (this._history.index(this._currentFile.url()) && currentProjectType === snippetsProjectType &&
+        addedProjectType !== snippetsProjectType)
+      this._innerShowFile(uiSourceCode, false);
+  }
+
+  /**
+   * @param {!WebInspector.UISourceCode} uiSourceCode
+   */
+  removeUISourceCode(uiSourceCode) {
+    this.removeUISourceCodes([uiSourceCode]);
+  }
+
+  /**
+   * @param {!Array.<!WebInspector.UISourceCode>} uiSourceCodes
+   */
+  removeUISourceCodes(uiSourceCodes) {
+    var tabIds = [];
+    for (var i = 0; i < uiSourceCodes.length; ++i) {
+      var uiSourceCode = uiSourceCodes[i];
+      var tabId = this._tabIds.get(uiSourceCode);
+      if (tabId)
+        tabIds.push(tabId);
+    }
+    this._tabbedPane.closeTabs(tabIds);
+  }
 
-    /**
-     * @param {!WebInspector.UISourceCode} uiSourceCode
-     * @return {string}
-     */
-    _titleForFile: function(uiSourceCode)
-    {
-        var binding = WebInspector.persistence.binding(uiSourceCode);
-        var titleUISourceCode = binding ? binding.fileSystem : uiSourceCode;
-        var maxDisplayNameLength = 30;
-        var title = titleUISourceCode.displayName(true).trimMiddle(maxDisplayNameLength);
-        if (uiSourceCode.isDirty() || WebInspector.persistence.hasUnsavedCommittedChanges(uiSourceCode))
-            title += "*";
-        return title;
-    },
+  /**
+   * @param {!WebInspector.UISourceCode} uiSourceCode
+   */
+  _editorClosedByUserAction(uiSourceCode) {
+    this._history.remove(uiSourceCode.url());
+    this._updateHistory();
+  }
 
-    /**
-     * @param {string} id
-     * @param {string} nextTabId
-     */
-    _maybeCloseTab: function(id, nextTabId)
-    {
-        var uiSourceCode = this._files[id];
-        var shouldPrompt = uiSourceCode.isDirty() && uiSourceCode.project().canSetFileContent();
-        // FIXME: this should be replaced with common Save/Discard/Cancel dialog.
-        if (!shouldPrompt || confirm(WebInspector.UIString("Are you sure you want to close unsaved file: %s?", uiSourceCode.name()))) {
-            uiSourceCode.resetWorkingCopy();
-            var previousView = this._currentView;
-            if (nextTabId)
-                this._tabbedPane.selectTab(nextTabId, true);
-            this._tabbedPane.closeTab(id, true);
-            return true;
-        }
-        return false;
-    },
+  _editorSelectedByUserAction() {
+    this._updateHistory();
+  }
 
-    /**
-     * @param {!Array.<string>} ids
-     * @param {boolean=} forceCloseDirtyTabs
-     */
-    _closeTabs: function(ids, forceCloseDirtyTabs)
-    {
-        var dirtyTabs = [];
-        var cleanTabs = [];
-        for (var i = 0; i < ids.length; ++i) {
-            var id = ids[i];
-            var uiSourceCode = this._files[id];
-            if (!forceCloseDirtyTabs && uiSourceCode.isDirty())
-                dirtyTabs.push(id);
-            else
-                cleanTabs.push(id);
-        }
-        if (dirtyTabs.length)
-            this._tabbedPane.selectTab(dirtyTabs[0], true);
-        this._tabbedPane.closeTabs(cleanTabs, true);
-        for (var i = 0; i < dirtyTabs.length; ++i) {
-            var nextTabId = i + 1 < dirtyTabs.length ? dirtyTabs[i + 1] : null;
-            if (!this._maybeCloseTab(dirtyTabs[i], nextTabId))
-                break;
-        }
-    },
+  _updateHistory() {
+    var tabIds =
+        this._tabbedPane.lastOpenedTabIds(WebInspector.TabbedEditorContainer.maximalPreviouslyViewedFilesCount);
 
     /**
      * @param {string} tabId
-     * @param {!WebInspector.ContextMenu} contextMenu
-     */
-    _onContextMenu: function(tabId, contextMenu)
-    {
-        var uiSourceCode = this._files[tabId];
-        if (uiSourceCode)
-            contextMenu.appendApplicableItems(uiSourceCode);
-    },
-
-    /**
-     * @param {!WebInspector.UISourceCode} uiSourceCode
-     */
-    addUISourceCode: function(uiSourceCode)
-    {
-        var uri = uiSourceCode.url();
-        var index = this._history.index(uri);
-        if (index === -1)
-            return;
-
-        if (!this._tabIds.has(uiSourceCode))
-            this._appendFileTab(uiSourceCode, false);
-
-        // Select tab if this file was the last to be shown.
-        if (!index) {
-            this._innerShowFile(uiSourceCode, false);
-            return;
-        }
-
-        if (!this._currentFile)
-            return;
-        var currentProjectType = this._currentFile.project().type();
-        var addedProjectType = uiSourceCode.project().type();
-        var snippetsProjectType = WebInspector.projectTypes.Snippets;
-        if (this._history.index(this._currentFile.url()) && currentProjectType === snippetsProjectType && addedProjectType !== snippetsProjectType)
-            this._innerShowFile(uiSourceCode, false);
-    },
-
-    /**
-     * @param {!WebInspector.UISourceCode} uiSourceCode
-     */
-    removeUISourceCode: function(uiSourceCode)
-    {
-        this.removeUISourceCodes([uiSourceCode]);
-    },
-
-    /**
-     * @param {!Array.<!WebInspector.UISourceCode>} uiSourceCodes
-     */
-    removeUISourceCodes: function(uiSourceCodes)
-    {
-        var tabIds = [];
-        for (var i = 0; i < uiSourceCodes.length; ++i) {
-            var uiSourceCode = uiSourceCodes[i];
-            var tabId = this._tabIds.get(uiSourceCode);
-            if (tabId)
-                tabIds.push(tabId);
-        }
-        this._tabbedPane.closeTabs(tabIds);
-    },
-
-    /**
-     * @param {!WebInspector.UISourceCode} uiSourceCode
-     */
-    _editorClosedByUserAction: function(uiSourceCode)
-    {
-        this._history.remove(uiSourceCode.url());
-        this._updateHistory();
-    },
-
-    _editorSelectedByUserAction: function()
-    {
-        this._updateHistory();
-    },
-
-    _updateHistory: function()
-    {
-        var tabIds = this._tabbedPane.lastOpenedTabIds(WebInspector.TabbedEditorContainer.maximalPreviouslyViewedFilesCount);
-
-        /**
-         * @param {string} tabId
-         * @this {WebInspector.TabbedEditorContainer}
-         */
-        function tabIdToURI(tabId)
-        {
-            return this._files[tabId].url();
-        }
-
-        this._history.update(tabIds.map(tabIdToURI.bind(this)));
-        this._history.save(this._previouslyViewedFilesSetting);
-    },
-
-    /**
-     * @param {!WebInspector.UISourceCode} uiSourceCode
-     * @return {string}
-     */
-    _tooltipForFile: function(uiSourceCode)
-    {
-        uiSourceCode = WebInspector.persistence.fileSystem(uiSourceCode) || uiSourceCode;
-        return uiSourceCode.url();
-    },
-
-    /**
-     * @param {!WebInspector.UISourceCode} uiSourceCode
-     * @param {boolean=} userGesture
-     * @param {number=} index
-     * @return {string}
-     */
-    _appendFileTab: function(uiSourceCode, userGesture, index)
-    {
-        var view = this._delegate.viewForFile(uiSourceCode);
-        var title = this._titleForFile(uiSourceCode);
-        var tooltip = this._tooltipForFile(uiSourceCode);
-
-        var tabId = this._generateTabId();
-        this._tabIds.set(uiSourceCode, tabId);
-        this._files[tabId] = uiSourceCode;
-
-        var savedSelectionRange = this._history.selectionRange(uiSourceCode.url());
-        var savedScrollLineNumber = this._history.scrollLineNumber(uiSourceCode.url());
-        this._restoreEditorProperties(view, savedSelectionRange, savedScrollLineNumber);
-
-        this._tabbedPane.appendTab(tabId, title, view, tooltip, userGesture, undefined, index);
-
-        this._updateFileTitle(uiSourceCode);
-        this._addUISourceCodeListeners(uiSourceCode);
-        return tabId;
-    },
-
-    /**
-     * @param {!WebInspector.Widget} editorView
-     * @param {!WebInspector.TextRange=} selection
-     * @param {number=} firstLineNumber
-     */
-    _restoreEditorProperties: function(editorView, selection, firstLineNumber)
-    {
-        var sourceFrame = editorView instanceof WebInspector.SourceFrame ? /** @type {!WebInspector.SourceFrame} */ (editorView) : null;
-        if (!sourceFrame)
-            return;
-        if (selection)
-            sourceFrame.setSelection(selection);
-        if (typeof firstLineNumber === "number")
-            sourceFrame.scrollToLine(firstLineNumber);
-    },
-
-    /**
-     * @param {!WebInspector.Event} event
-     */
-    _tabClosed: function(event)
-    {
-        var tabId = /** @type {string} */ (event.data.tabId);
-        var userGesture = /** @type {boolean} */ (event.data.isUserGesture);
-
-        var uiSourceCode = this._files[tabId];
-        if (this._currentFile === uiSourceCode) {
-            this._removeViewListeners();
-            delete this._currentView;
-            delete this._currentFile;
-        }
-        this._tabIds.remove(uiSourceCode);
-        delete this._files[tabId];
-
-        this._removeUISourceCodeListeners(uiSourceCode);
-
-        this.dispatchEventToListeners(WebInspector.TabbedEditorContainer.Events.EditorClosed, uiSourceCode);
-
-        if (userGesture)
-            this._editorClosedByUserAction(uiSourceCode);
-    },
-
-    /**
-     * @param {!WebInspector.Event} event
+     * @this {WebInspector.TabbedEditorContainer}
      */
-    _tabSelected: function(event)
-    {
-        var tabId = /** @type {string} */ (event.data.tabId);
-        var userGesture = /** @type {boolean} */ (event.data.isUserGesture);
-
-        var uiSourceCode = this._files[tabId];
-        this._innerShowFile(uiSourceCode, userGesture);
-    },
-
-    /**
-     * @param {!WebInspector.UISourceCode} uiSourceCode
-     */
-    _addUISourceCodeListeners: function(uiSourceCode)
-    {
-        uiSourceCode.addEventListener(WebInspector.UISourceCode.Events.TitleChanged, this._uiSourceCodeTitleChanged, this);
-        uiSourceCode.addEventListener(WebInspector.UISourceCode.Events.WorkingCopyChanged, this._uiSourceCodeWorkingCopyChanged, this);
-        uiSourceCode.addEventListener(WebInspector.UISourceCode.Events.WorkingCopyCommitted, this._uiSourceCodeWorkingCopyCommitted, this);
-    },
-
-    /**
-     * @param {!WebInspector.UISourceCode} uiSourceCode
-     */
-    _removeUISourceCodeListeners: function(uiSourceCode)
-    {
-        uiSourceCode.removeEventListener(WebInspector.UISourceCode.Events.TitleChanged, this._uiSourceCodeTitleChanged, this);
-        uiSourceCode.removeEventListener(WebInspector.UISourceCode.Events.WorkingCopyChanged, this._uiSourceCodeWorkingCopyChanged, this);
-        uiSourceCode.removeEventListener(WebInspector.UISourceCode.Events.WorkingCopyCommitted, this._uiSourceCodeWorkingCopyCommitted, this);
-    },
+    function tabIdToURI(tabId) {
+      return this._files[tabId].url();
+    }
 
-    /**
-     * @param {!WebInspector.UISourceCode} uiSourceCode
-     */
-    _updateFileTitle: function(uiSourceCode)
-    {
-        var tabId = this._tabIds.get(uiSourceCode);
-        if (tabId) {
-            var title = this._titleForFile(uiSourceCode);
-            this._tabbedPane.changeTabTitle(tabId, title);
-            if (WebInspector.persistence.hasUnsavedCommittedChanges(uiSourceCode))
-                this._tabbedPane.setTabIcon(tabId, "warning-icon", WebInspector.UIString("Changes to this file were not saved to file system."));
-            else
-                this._tabbedPane.setTabIcon(tabId, "");
-        }
-    },
-
-    _uiSourceCodeTitleChanged: function(event)
-    {
-        var uiSourceCode = /** @type {!WebInspector.UISourceCode} */ (event.target);
-        this._updateFileTitle(uiSourceCode);
-        this._updateHistory();
-    },
-
-    _uiSourceCodeWorkingCopyChanged: function(event)
-    {
-        var uiSourceCode = /** @type {!WebInspector.UISourceCode} */ (event.target);
-        this._updateFileTitle(uiSourceCode);
-    },
-
-    _uiSourceCodeWorkingCopyCommitted: function(event)
-    {
-        var uiSourceCode = /** @type {!WebInspector.UISourceCode} */ (event.target);
-        this._updateFileTitle(uiSourceCode);
-    },
+    this._history.update(tabIds.map(tabIdToURI.bind(this)));
+    this._history.save(this._previouslyViewedFilesSetting);
+  }
+
+  /**
+   * @param {!WebInspector.UISourceCode} uiSourceCode
+   * @return {string}
+   */
+  _tooltipForFile(uiSourceCode) {
+    uiSourceCode = WebInspector.persistence.fileSystem(uiSourceCode) || uiSourceCode;
+    return uiSourceCode.url();
+  }
+
+  /**
+   * @param {!WebInspector.UISourceCode} uiSourceCode
+   * @param {boolean=} userGesture
+   * @param {number=} index
+   * @return {string}
+   */
+  _appendFileTab(uiSourceCode, userGesture, index) {
+    var view = this._delegate.viewForFile(uiSourceCode);
+    var title = this._titleForFile(uiSourceCode);
+    var tooltip = this._tooltipForFile(uiSourceCode);
+
+    var tabId = this._generateTabId();
+    this._tabIds.set(uiSourceCode, tabId);
+    this._files[tabId] = uiSourceCode;
+
+    var savedSelectionRange = this._history.selectionRange(uiSourceCode.url());
+    var savedScrollLineNumber = this._history.scrollLineNumber(uiSourceCode.url());
+    this._restoreEditorProperties(view, savedSelectionRange, savedScrollLineNumber);
+
+    this._tabbedPane.appendTab(tabId, title, view, tooltip, userGesture, undefined, index);
+
+    this._updateFileTitle(uiSourceCode);
+    this._addUISourceCodeListeners(uiSourceCode);
+    return tabId;
+  }
+
+  /**
+   * @param {!WebInspector.Widget} editorView
+   * @param {!WebInspector.TextRange=} selection
+   * @param {number=} firstLineNumber
+   */
+  _restoreEditorProperties(editorView, selection, firstLineNumber) {
+    var sourceFrame =
+        editorView instanceof WebInspector.SourceFrame ? /** @type {!WebInspector.SourceFrame} */ (editorView) : null;
+    if (!sourceFrame)
+      return;
+    if (selection)
+      sourceFrame.setSelection(selection);
+    if (typeof firstLineNumber === 'number')
+      sourceFrame.scrollToLine(firstLineNumber);
+  }
+
+  /**
+   * @param {!WebInspector.Event} event
+   */
+  _tabClosed(event) {
+    var tabId = /** @type {string} */ (event.data.tabId);
+    var userGesture = /** @type {boolean} */ (event.data.isUserGesture);
+
+    var uiSourceCode = this._files[tabId];
+    if (this._currentFile === uiSourceCode) {
+      this._removeViewListeners();
+      delete this._currentView;
+      delete this._currentFile;
+    }
+    this._tabIds.remove(uiSourceCode);
+    delete this._files[tabId];
+
+    this._removeUISourceCodeListeners(uiSourceCode);
+
+    this.dispatchEventToListeners(WebInspector.TabbedEditorContainer.Events.EditorClosed, uiSourceCode);
+
+    if (userGesture)
+      this._editorClosedByUserAction(uiSourceCode);
+  }
+
+  /**
+   * @param {!WebInspector.Event} event
+   */
+  _tabSelected(event) {
+    var tabId = /** @type {string} */ (event.data.tabId);
+    var userGesture = /** @type {boolean} */ (event.data.isUserGesture);
+
+    var uiSourceCode = this._files[tabId];
+    this._innerShowFile(uiSourceCode, userGesture);
+  }
+
+  /**
+   * @param {!WebInspector.UISourceCode} uiSourceCode
+   */
+  _addUISourceCodeListeners(uiSourceCode) {
+    uiSourceCode.addEventListener(WebInspector.UISourceCode.Events.TitleChanged, this._uiSourceCodeTitleChanged, this);
+    uiSourceCode.addEventListener(
+        WebInspector.UISourceCode.Events.WorkingCopyChanged, this._uiSourceCodeWorkingCopyChanged, this);
+    uiSourceCode.addEventListener(
+        WebInspector.UISourceCode.Events.WorkingCopyCommitted, this._uiSourceCodeWorkingCopyCommitted, this);
+  }
+
+  /**
+   * @param {!WebInspector.UISourceCode} uiSourceCode
+   */
+  _removeUISourceCodeListeners(uiSourceCode) {
+    uiSourceCode.removeEventListener(
+        WebInspector.UISourceCode.Events.TitleChanged, this._uiSourceCodeTitleChanged, this);
+    uiSourceCode.removeEventListener(
+        WebInspector.UISourceCode.Events.WorkingCopyChanged, this._uiSourceCodeWorkingCopyChanged, this);
+    uiSourceCode.removeEventListener(
+        WebInspector.UISourceCode.Events.WorkingCopyCommitted, this._uiSourceCodeWorkingCopyCommitted, this);
+  }
+
+  /**
+   * @param {!WebInspector.UISourceCode} uiSourceCode
+   */
+  _updateFileTitle(uiSourceCode) {
+    var tabId = this._tabIds.get(uiSourceCode);
+    if (tabId) {
+      var title = this._titleForFile(uiSourceCode);
+      this._tabbedPane.changeTabTitle(tabId, title);
+      if (WebInspector.persistence.hasUnsavedCommittedChanges(uiSourceCode))
+        this._tabbedPane.setTabIcon(
+            tabId, 'warning-icon', WebInspector.UIString('Changes to this file were not saved to file system.'));
+      else
+        this._tabbedPane.setTabIcon(tabId, '');
+    }
+  }
+
+  _uiSourceCodeTitleChanged(event) {
+    var uiSourceCode = /** @type {!WebInspector.UISourceCode} */ (event.target);
+    this._updateFileTitle(uiSourceCode);
+    this._updateHistory();
+  }
+
+  _uiSourceCodeWorkingCopyChanged(event) {
+    var uiSourceCode = /** @type {!WebInspector.UISourceCode} */ (event.target);
+    this._updateFileTitle(uiSourceCode);
+  }
+
+  _uiSourceCodeWorkingCopyCommitted(event) {
+    var uiSourceCode = /** @type {!WebInspector.UISourceCode} */ (event.target);
+    this._updateFileTitle(uiSourceCode);
+  }
+
+  /**
+   * @return {string}
+   */
+  _generateTabId() {
+    return 'tab_' + (WebInspector.TabbedEditorContainer._tabId++);
+  }
+
+  /**
+   * @return {?WebInspector.UISourceCode} uiSourceCode
+   */
+  currentFile() {
+    return this._currentFile || null;
+  }
+};
 
-    /**
-     * @return {string}
-     */
-    _generateTabId: function()
-    {
-        return "tab_" + (WebInspector.TabbedEditorContainer._tabId++);
-    },
+/** @enum {symbol} */
+WebInspector.TabbedEditorContainer.Events = {
+  EditorSelected: Symbol('EditorSelected'),
+  EditorClosed: Symbol('EditorClosed')
+};
 
-    /**
-     * @return {?WebInspector.UISourceCode} uiSourceCode
-     */
-    currentFile: function()
-    {
-        return this._currentFile || null;
-    },
+WebInspector.TabbedEditorContainer._tabId = 0;
 
-    __proto__: WebInspector.Object.prototype
-};
+WebInspector.TabbedEditorContainer.maximalPreviouslyViewedFilesCount = 30;
 
 /**
- * @constructor
- * @param {string} url
- * @param {!WebInspector.TextRange=} selectionRange
- * @param {number=} scrollLineNumber
+ * @unrestricted
  */
-WebInspector.TabbedEditorContainer.HistoryItem = function(url, selectionRange, scrollLineNumber)
-{
+WebInspector.TabbedEditorContainer.HistoryItem = class {
+  /**
+   * @param {string} url
+   * @param {!WebInspector.TextRange=} selectionRange
+   * @param {number=} scrollLineNumber
+   */
+  constructor(url, selectionRange, scrollLineNumber) {
     /** @const */ this.url = url;
-    /** @const */ this._isSerializable = url.length < WebInspector.TabbedEditorContainer.HistoryItem.serializableUrlLengthLimit;
+    /** @const */ this._isSerializable =
+        url.length < WebInspector.TabbedEditorContainer.HistoryItem.serializableUrlLengthLimit;
     this.selectionRange = selectionRange;
     this.scrollLineNumber = scrollLineNumber;
+  }
+
+  /**
+   * @param {!Object} serializedHistoryItem
+   * @return {!WebInspector.TabbedEditorContainer.HistoryItem}
+   */
+  static fromObject(serializedHistoryItem) {
+    var selectionRange = serializedHistoryItem.selectionRange ?
+        WebInspector.TextRange.fromObject(serializedHistoryItem.selectionRange) :
+        undefined;
+    return new WebInspector.TabbedEditorContainer.HistoryItem(
+        serializedHistoryItem.url, selectionRange, serializedHistoryItem.scrollLineNumber);
+  }
+
+  /**
+   * @return {?Object}
+   */
+  serializeToObject() {
+    if (!this._isSerializable)
+      return null;
+    var serializedHistoryItem = {};
+    serializedHistoryItem.url = this.url;
+    serializedHistoryItem.selectionRange = this.selectionRange;
+    serializedHistoryItem.scrollLineNumber = this.scrollLineNumber;
+    return serializedHistoryItem;
+  }
 };
 
 WebInspector.TabbedEditorContainer.HistoryItem.serializableUrlLengthLimit = 4096;
 
-/**
- * @param {!Object} serializedHistoryItem
- * @return {!WebInspector.TabbedEditorContainer.HistoryItem}
- */
-WebInspector.TabbedEditorContainer.HistoryItem.fromObject = function(serializedHistoryItem)
-{
-    var selectionRange = serializedHistoryItem.selectionRange ? WebInspector.TextRange.fromObject(serializedHistoryItem.selectionRange) : undefined;
-    return new WebInspector.TabbedEditorContainer.HistoryItem(serializedHistoryItem.url, selectionRange, serializedHistoryItem.scrollLineNumber);
-};
-
-WebInspector.TabbedEditorContainer.HistoryItem.prototype = {
-    /**
-     * @return {?Object}
-     */
-    serializeToObject: function()
-    {
-        if (!this._isSerializable)
-            return null;
-        var serializedHistoryItem = {};
-        serializedHistoryItem.url = this.url;
-        serializedHistoryItem.selectionRange = this.selectionRange;
-        serializedHistoryItem.scrollLineNumber = this.scrollLineNumber;
-        return serializedHistoryItem;
-    }
-};
 
 /**
- * @constructor
- * @param {!Array.<!WebInspector.TabbedEditorContainer.HistoryItem>} items
+ * @unrestricted
  */
-WebInspector.TabbedEditorContainer.History = function(items)
-{
+WebInspector.TabbedEditorContainer.History = class {
+  /**
+   * @param {!Array.<!WebInspector.TabbedEditorContainer.HistoryItem>} items
+   */
+  constructor(items) {
     this._items = items;
     this._rebuildItemIndex();
-};
+  }
 
-/**
- * @param {!Array.<!Object>} serializedHistory
- * @return {!WebInspector.TabbedEditorContainer.History}
- */
-WebInspector.TabbedEditorContainer.History.fromObject = function(serializedHistory)
-{
+  /**
+   * @param {!Array.<!Object>} serializedHistory
+   * @return {!WebInspector.TabbedEditorContainer.History}
+   */
+  static fromObject(serializedHistory) {
     var items = [];
     for (var i = 0; i < serializedHistory.length; ++i)
-        items.push(WebInspector.TabbedEditorContainer.HistoryItem.fromObject(serializedHistory[i]));
+      items.push(WebInspector.TabbedEditorContainer.HistoryItem.fromObject(serializedHistory[i]));
     return new WebInspector.TabbedEditorContainer.History(items);
-};
-
-WebInspector.TabbedEditorContainer.History.prototype = {
-    /**
-     * @param {string} url
-     * @return {number}
-     */
-    index: function(url)
-    {
-        return this._itemsIndex.has(url) ? /** @type {number} */(this._itemsIndex.get(url)) : -1;
-    },
-
-    _rebuildItemIndex: function()
-    {
-        /** @type {!Map<string, number>} */
-        this._itemsIndex = new Map();
-        for (var i = 0; i < this._items.length; ++i) {
-            console.assert(!this._itemsIndex.has(this._items[i].url));
-            this._itemsIndex.set(this._items[i].url, i);
-        }
-    },
-
-    /**
-     * @param {string} url
-     * @return {!WebInspector.TextRange|undefined}
-     */
-    selectionRange: function(url)
-    {
-        var index = this.index(url);
-        return index !== -1 ? this._items[index].selectionRange : undefined;
-    },
-
-    /**
-     * @param {string} url
-     * @param {!WebInspector.TextRange=} selectionRange
-     */
-    updateSelectionRange: function(url, selectionRange)
-    {
-        if (!selectionRange)
-            return;
-        var index = this.index(url);
-        if (index === -1)
-            return;
-        this._items[index].selectionRange = selectionRange;
-    },
-
-    /**
-     * @param {string} url
-     * @return {number|undefined}
-     */
-    scrollLineNumber: function(url)
-    {
-        var index = this.index(url);
-        return index !== -1 ? this._items[index].scrollLineNumber : undefined;
-    },
-
-    /**
-     * @param {string} url
-     * @param {number} scrollLineNumber
-     */
-    updateScrollLineNumber: function(url, scrollLineNumber)
-    {
-        var index = this.index(url);
-        if (index === -1)
-            return;
-        this._items[index].scrollLineNumber = scrollLineNumber;
-    },
-
-    /**
-     * @param {!Array.<string>} urls
-     */
-    update: function(urls)
-    {
-        for (var i = urls.length - 1; i >= 0; --i) {
-            var index = this.index(urls[i]);
-            var item;
-            if (index !== -1) {
-                item = this._items[index];
-                this._items.splice(index, 1);
-            } else
-                item = new WebInspector.TabbedEditorContainer.HistoryItem(urls[i]);
-            this._items.unshift(item);
-            this._rebuildItemIndex();
-        }
-    },
-
-    /**
-     * @param {string} url
-     */
-    remove: function(url)
-    {
-        var index = this.index(url);
-        if (index !== -1) {
-            this._items.splice(index, 1);
-            this._rebuildItemIndex();
-        }
-    },
-
-    /**
-     * @param {!WebInspector.Setting} setting
-     */
-    save: function(setting)
-    {
-        setting.set(this._serializeToObject());
-    },
-
-    /**
-     * @return {!Array.<!Object>}
-     */
-    _serializeToObject: function()
-    {
-        var serializedHistory = [];
-        for (var i = 0; i < this._items.length; ++i) {
-            var serializedItem = this._items[i].serializeToObject();
-            if (serializedItem)
-                serializedHistory.push(serializedItem);
-            if (serializedHistory.length === WebInspector.TabbedEditorContainer.maximalPreviouslyViewedFilesCount)
-                break;
-        }
-        return serializedHistory;
-    },
-
-
-    /**
-     * @return {!Array.<string>}
-     */
-    _urls: function()
-    {
-        var result = [];
-        for (var i = 0; i < this._items.length; ++i)
-            result.push(this._items[i].url);
-        return result;
+  }
+
+  /**
+   * @param {string} url
+   * @return {number}
+   */
+  index(url) {
+    return this._itemsIndex.has(url) ? /** @type {number} */ (this._itemsIndex.get(url)) : -1;
+  }
+
+  _rebuildItemIndex() {
+    /** @type {!Map<string, number>} */
+    this._itemsIndex = new Map();
+    for (var i = 0; i < this._items.length; ++i) {
+      console.assert(!this._itemsIndex.has(this._items[i].url));
+      this._itemsIndex.set(this._items[i].url, i);
+    }
+  }
+
+  /**
+   * @param {string} url
+   * @return {!WebInspector.TextRange|undefined}
+   */
+  selectionRange(url) {
+    var index = this.index(url);
+    return index !== -1 ? this._items[index].selectionRange : undefined;
+  }
+
+  /**
+   * @param {string} url
+   * @param {!WebInspector.TextRange=} selectionRange
+   */
+  updateSelectionRange(url, selectionRange) {
+    if (!selectionRange)
+      return;
+    var index = this.index(url);
+    if (index === -1)
+      return;
+    this._items[index].selectionRange = selectionRange;
+  }
+
+  /**
+   * @param {string} url
+   * @return {number|undefined}
+   */
+  scrollLineNumber(url) {
+    var index = this.index(url);
+    return index !== -1 ? this._items[index].scrollLineNumber : undefined;
+  }
+
+  /**
+   * @param {string} url
+   * @param {number} scrollLineNumber
+   */
+  updateScrollLineNumber(url, scrollLineNumber) {
+    var index = this.index(url);
+    if (index === -1)
+      return;
+    this._items[index].scrollLineNumber = scrollLineNumber;
+  }
+
+  /**
+   * @param {!Array.<string>} urls
+   */
+  update(urls) {
+    for (var i = urls.length - 1; i >= 0; --i) {
+      var index = this.index(urls[i]);
+      var item;
+      if (index !== -1) {
+        item = this._items[index];
+        this._items.splice(index, 1);
+      } else
+        item = new WebInspector.TabbedEditorContainer.HistoryItem(urls[i]);
+      this._items.unshift(item);
+      this._rebuildItemIndex();
+    }
+  }
+
+  /**
+   * @param {string} url
+   */
+  remove(url) {
+    var index = this.index(url);
+    if (index !== -1) {
+      this._items.splice(index, 1);
+      this._rebuildItemIndex();
     }
+  }
+
+  /**
+   * @param {!WebInspector.Setting} setting
+   */
+  save(setting) {
+    setting.set(this._serializeToObject());
+  }
+
+  /**
+   * @return {!Array.<!Object>}
+   */
+  _serializeToObject() {
+    var serializedHistory = [];
+    for (var i = 0; i < this._items.length; ++i) {
+      var serializedItem = this._items[i].serializeToObject();
+      if (serializedItem)
+        serializedHistory.push(serializedItem);
+      if (serializedHistory.length === WebInspector.TabbedEditorContainer.maximalPreviouslyViewedFilesCount)
+        break;
+    }
+    return serializedHistory;
+  }
+
+  /**
+   * @return {!Array.<string>}
+   */
+  _urls() {
+    var result = [];
+    for (var i = 0; i < this._items.length; ++i)
+      result.push(this._items[i].url);
+    return result;
+  }
 };
 
+
 /**
- * @constructor
  * @implements {WebInspector.TabbedPaneTabDelegate}
- * @param {!WebInspector.TabbedEditorContainer} editorContainer
+ * @unrestricted
  */
-WebInspector.EditorContainerTabDelegate = function(editorContainer)
-{
+WebInspector.EditorContainerTabDelegate = class {
+  /**
+   * @param {!WebInspector.TabbedEditorContainer} editorContainer
+   */
+  constructor(editorContainer) {
     this._editorContainer = editorContainer;
-};
-
-WebInspector.EditorContainerTabDelegate.prototype = {
-    /**
-     * @override
-     * @param {!WebInspector.TabbedPane} tabbedPane
-     * @param {!Array.<string>} ids
-     */
-    closeTabs: function(tabbedPane, ids)
-    {
-        this._editorContainer._closeTabs(ids);
-    },
-
-    /**
-     * @override
-     * @param {string} tabId
-     * @param {!WebInspector.ContextMenu} contextMenu
-     */
-    onContextMenu: function(tabId, contextMenu)
-    {
-        this._editorContainer._onContextMenu(tabId, contextMenu);
-    }
+  }
+
+  /**
+   * @override
+   * @param {!WebInspector.TabbedPane} tabbedPane
+   * @param {!Array.<string>} ids
+   */
+  closeTabs(tabbedPane, ids) {
+    this._editorContainer._closeTabs(ids);
+  }
+
+  /**
+   * @override
+   * @param {string} tabId
+   * @param {!WebInspector.ContextMenu} contextMenu
+   */
+  onContextMenu(tabId, contextMenu) {
+    this._editorContainer._onContextMenu(tabId, contextMenu);
+  }
 };