DevTools: restore shortcuts to switch devtool panel left/right

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

 /*
  * Copyright (C) 2010 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 315 matching lines @@
 
     this._updateTabElements();
     if (focused)
       this.focus();
 
     var eventData = {tabId: id, view: tab.view, isUserGesture: userGesture};
     this.dispatchEventToListeners(UI.TabbedPane.Events.TabSelected, eventData);
     return true;
   }
 
+  selectNextTab() {
+    for (var i = 0; i < this._tabs.length; ++i) {
+      if (this._tabs[i] === this._currentTab) {

[caseq, 2017/01/23 22:48:27]

this._tabs.indexOf(this._currentTab)

+        var nextIndex = (i + 1) % this._tabs.length;

[caseq, 2017/01/23 22:48:27]

let's extract this to a parameter.

+        this.selectTab(this._tabs[nextIndex].id, true);
+        break;
+      }
+    }
+  }
+
+  selectPrevTab() {
+    for (var i = 0; i < this._tabs.length; ++i) {
+      if (this._tabs[i] === this._currentTab) {
+        var prevIndex = (i - 1 + this._tabs.length) % this._tabs.length;
+        this.selectTab(this._tabs[prevIndex].id, true);
+        break;
+      }
+    }
+  }
+
   /**
    * @param {number} tabsCount
    * @return {!Array.<string>}
    */
   lastOpenedTabIds(tabsCount) {
     function tabToTabId(tab) {
       return tab.id;
     }
 
     return this._tabsHistory.slice(0, tabsCount).map(tabToTabId);
@@ skipping 857 matching lines @@
    * @param {!Array.<string>} ids
    */
   closeTabs(tabbedPane, ids) {},
 
   /**
    * @param {string} tabId
    * @param {!UI.ContextMenu} contextMenu
    */
   onContextMenu(tabId, contextMenu) {}
 };