trace-viewer/src/base.js - platform/external/chromium-trace - Git at Google

 // Copyright (c) 2012 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.

 'use strict';


 /**
  * The global object.
  * @type {!Object}
  * @const
  */
 var global = this;


 /** Platform, package, object property, and Event support. */
 this.base = (function() {

   /**
    * Base path for modules. Used to form URLs for module 'require' requests.
    */
   var moduleBasePath = '.';
   function setModuleBasePath(path) {
     if (path[path.length - 1] == '/')
       path = path.substring(0, path.length - 1);
     moduleBasePath = path;
   }


   function mLog(text, opt_indentLevel) {
     if (true)
       return;

     var spacing = '';
     var indentLevel = opt_indentLevel || 0;
     for (var i = 0; i < indentLevel; i++)
       spacing += ' ';
     console.log(spacing + text);
   }

   /**
    * Builds an object structure for the provided namespace path,
    * ensuring that names that already exist are not overwritten. For
    * example:
    * 'a.b.c' -> a = {};a.b={};a.b.c={};
    * @param {string} name Name of the object that this file defines.
    * @param {*=} opt_object The object to expose at the end of the path.
    * @param {Object=} opt_objectToExportTo The object to add the path to;
    *     default is {@code global}.
    * @private
    */
   function exportPath(name, opt_object, opt_objectToExportTo) {
     var parts = name.split('.');
     var cur = opt_objectToExportTo || global;

     for (var part; parts.length && (part = parts.shift());) {
       if (!parts.length && opt_object !== undefined) {
         // last part and we have an object; use it
         cur[part] = opt_object;
       } else if (part in cur) {
         cur = cur[part];
       } else {
         cur = cur[part] = {};
       }
     }
     return cur;
   };

   var didLoadModules = false;
   var moduleDependencies = {};
   var moduleStylesheets = {};

   function addModuleDependency(moduleName, dependentModuleName) {
     if (!moduleDependencies[moduleName])
       moduleDependencies[moduleName] = [];

     var dependentModules = moduleDependencies[moduleName];
     var found = false;
     for (var i = 0; i < dependentModules.length; i++)
       if (dependentModules[i] == dependentModuleName)
         found = true;
       if (!found)
         dependentModules.push(dependentModuleName);
   }

   function addModuleStylesheet(moduleName, stylesheetName) {
     if (!moduleStylesheets[moduleName])
       moduleStylesheets[moduleName] = [];

     var stylesheets = moduleStylesheets[moduleName];
     var found = false;
     for (var i = 0; i < stylesheets.length; i++)
       if (stylesheets[i] == stylesheetName)
         found = true;
       if (!found)
         stylesheets.push(stylesheetName);
   }

   function ensureDepsLoaded() {
     if (didLoadModules)
       return;
     didLoadModules = true;

     var req = new XMLHttpRequest();
     var src = moduleBasePath + '/' + 'deps.js';
     req.open('GET', src, false);
     req.send(null);
     if (req.status != 200)
       throw new Error('Could not find ' + deps +
                       '. Run calcdeps.py and try again.');

     base.addModuleStylesheet = addModuleStylesheet;
     base.addModuleDependency = addModuleDependency;
     try {
       // By construction, the deps file should call addModuleDependency.
       eval(req.responseText);
     } catch (e) {
       throw new Error('When loading deps, got ' + e.stack ? e.stack : e);
     }
     delete base.addModuleDependency;
     delete base.addModuleStylesheet;
   }

   var moduleLoadStatus = {};
   function require(dependentModuleName, opt_indentLevel) {
     var indentLevel = opt_indentLevel || 0;

     if (window.FLATTENED) {
       if (!window.FLATTENED[dependentModuleName])
         throw new Error('Somehow, module ' + dependentModuleName +
                         ' didn\'t get flattened!');
       return;
     }
     ensureDepsLoaded();

     mLog('require(' + dependentModuleName + ')', indentLevel);

     if (moduleLoadStatus[dependentModuleName] == 'APPENDED')
       return;
     if (moduleLoadStatus[dependentModuleName] == 'RESOLVING')
       throw new Error('Circular dependency betwen modules. Cannot continue!');
     moduleLoadStatus[dependentModuleName] = 'RESOLVING';

     // Load the module stylesheet first.
     var stylesheets = moduleStylesheets[dependentModuleName] || [];
     for (var i = 0; i < stylesheets.length; i++)
       requireStylesheet(stylesheets[i]);

     // Load the module's dependent scripts after.
     var dependentModules =
         moduleDependencies[dependentModuleName] || [];
     for (var i = 0; i < dependentModules.length; i++)
       require(dependentModules[i], indentLevel + 1);

     mLog('load(' + dependentModuleName + ')', indentLevel);
     // Load the module itself.
     var localPath = dependentModuleName.replace(/\./g, '/') + '.js';
     var src = moduleBasePath + '/' + localPath;
     var text = '<script type="text/javascript" src="' + src +
         '"></' + 'script>';
     base.doc.write(text);
     moduleLoadStatus[dependentModuleName] = 'APPENDED';
   }

   var stylesheetLoadStatus = {};
   function requireStylesheet(dependentStylesheetName) {
     if (window.FLATTENED)
       return;

     if (stylesheetLoadStatus[dependentStylesheetName])
       return;
     stylesheetLoadStatus[dependentStylesheetName] = true;
     var localPath = dependentStylesheetName.replace(/\./g, '/') + '.css';
     var stylesheetPath = moduleBasePath + '/' + localPath;

     var linkEl = document.createElement('link');
     linkEl.setAttribute('rel', 'stylesheet');
     linkEl.setAttribute('href', stylesheetPath);
     base.doc.head.appendChild(linkEl);
   }

   function exportTo(namespace, fn) {
     var obj = exportPath(namespace);
     try {
       var exports = fn();
     } catch (e) {
       console.log('While running exports for ', name, ':');
       console.log(e.stack || e);
       return;
     }

     for (var propertyName in exports) {
       // Maybe we should check the prototype chain here? The current usage
       // pattern is always using an object literal so we only care about own
       // properties.
       var propertyDescriptor = Object.getOwnPropertyDescriptor(exports,
                                                                propertyName);
       if (propertyDescriptor) {
         Object.defineProperty(obj, propertyName, propertyDescriptor);
         mLog('  +' + propertyName);
       }
     }
   };

   /**
    * Fires a property change event on the target.
    * @param {EventTarget} target The target to dispatch the event on.
    * @param {string} propertyName The name of the property that changed.
    * @param {*} newValue The new value for the property.
    * @param {*} oldValue The old value for the property.
    */
   function dispatchPropertyChange(target, propertyName, newValue, oldValue) {
     var e = new base.Event(propertyName + 'Change');
     e.propertyName = propertyName;
     e.newValue = newValue;
     e.oldValue = oldValue;
     target.dispatchEvent(e);
   }

   /**
    * Converts a camelCase javascript property name to a hyphenated-lower-case
    * attribute name.
    * @param {string} jsName The javascript camelCase property name.
    * @return {string} The equivalent hyphenated-lower-case attribute name.
    */
   function getAttributeName(jsName) {
     return jsName.replace(/([A-Z])/g, '-$1').toLowerCase();
   }

   /**
    * The kind of property to define in {@code defineProperty}.
    * @enum {number}
    * @const
    */
   var PropertyKind = {
     /**
      * Plain old JS property where the backing data is stored as a 'private'
      * field on the object.
      */
     JS: 'js',

     /**
      * The property backing data is stored as an attribute on an element.
      */
     ATTR: 'attr',

     /**
      * The property backing data is stored as an attribute on an element. If the
      * element has the attribute then the value is true.
      */
     BOOL_ATTR: 'boolAttr'
   };

   /**
    * Helper function for defineProperty that returns the getter to use for the
    * property.
    * @param {string} name The name of the property.
    * @param {base.PropertyKind} kind The kind of the property.
    * @return {function():*} The getter for the property.
    */
   function getGetter(name, kind) {
     switch (kind) {
       case PropertyKind.JS:
         var privateName = name + '_';
         return function() {
           return this[privateName];
         };
       case PropertyKind.ATTR:
         var attributeName = getAttributeName(name);
         return function() {
           return this.getAttribute(attributeName);
         };
       case PropertyKind.BOOL_ATTR:
         var attributeName = getAttributeName(name);
         return function() {
           return this.hasAttribute(attributeName);
         };
     }
   }

   /**
    * Helper function for defineProperty that returns the setter of the right
    * kind.
    * @param {string} name The name of the property we are defining the setter
    *     for.
    * @param {base.PropertyKind} kind The kind of property we are getting the
    *     setter for.
    * @param {function(*):void} opt_setHook A function to run after the property
    *     is set, but before the propertyChange event is fired.
    * @return {function(*):void} The function to use as a setter.
    */
   function getSetter(name, kind, opt_setHook) {
     switch (kind) {
       case PropertyKind.JS:
         var privateName = name + '_';
         return function(value) {
           var oldValue = this[privateName];
           if (value !== oldValue) {
             this[privateName] = value;
             if (opt_setHook)
               opt_setHook.call(this, value, oldValue);
             dispatchPropertyChange(this, name, value, oldValue);
           }
         };

       case PropertyKind.ATTR:
         var attributeName = getAttributeName(name);
         return function(value) {
           var oldValue = this[attributeName];
           if (value !== oldValue) {
             if (value == undefined)
               this.removeAttribute(attributeName);
             else
               this.setAttribute(attributeName, value);
             if (opt_setHook)
               opt_setHook.call(this, value, oldValue);
             dispatchPropertyChange(this, name, value, oldValue);
           }
         };

       case PropertyKind.BOOL_ATTR:
         var attributeName = getAttributeName(name);
         return function(value) {
           var oldValue = this[attributeName];
           if (value !== oldValue) {
             if (value)
               this.setAttribute(attributeName, name);
             else
               this.removeAttribute(attributeName);
             if (opt_setHook)
               opt_setHook.call(this, value, oldValue);
             dispatchPropertyChange(this, name, value, oldValue);
           }
         };
     }
   }

   /**
    * Defines a property on an object. When the setter changes the value a
    * property change event with the type {@code name + 'Change'} is fired.
    * @param {!Object} obj The object to define the property for.
    * @param {string} name The name of the property.
    * @param {base.PropertyKind=} opt_kind What kind of underlying storage to
    * use.
    * @param {function(*):void} opt_setHook A function to run after the
    *     property is set, but before the propertyChange event is fired.
    */
   function defineProperty(obj, name, opt_kind, opt_setHook) {
     if (typeof obj == 'function')
       obj = obj.prototype;

     var kind = opt_kind || PropertyKind.JS;

     if (!obj.__lookupGetter__(name))
       obj.__defineGetter__(name, getGetter(name, kind));

     if (!obj.__lookupSetter__(name))
       obj.__defineSetter__(name, getSetter(name, kind, opt_setHook));
   }

   /**
    * Counter for use with createUid
    */
   var uidCounter = 1;

   /**
    * @return {number} A new unique ID.
    */
   function createUid() {
     return uidCounter++;
   }

   /**
    * Returns a unique ID for the item. This mutates the item so it needs to be
    * an object
    * @param {!Object} item The item to get the unique ID for.
    * @return {number} The unique ID for the item.
    */
   function getUid(item) {
     if (item.hasOwnProperty('uid'))
       return item.uid;
     return item.uid = createUid();
   }

   /**
    * Dispatches a simple event on an event target.
    * @param {!EventTarget} target The event target to dispatch the event on.
    * @param {string} type The type of the event.
    * @param {boolean=} opt_bubbles Whether the event bubbles or not.
    * @param {boolean=} opt_cancelable Whether the default action of the event
    *     can be prevented.
    * @return {boolean} If any of the listeners called {@code preventDefault}
    *     during the dispatch this will return false.
    */
   function dispatchSimpleEvent(target, type, opt_bubbles, opt_cancelable) {
     var e = new base.Event(type, opt_bubbles, opt_cancelable);
     return target.dispatchEvent(e);
   }

   /**
    * Adds a {@code getInstance} static method that always return the same
    * instance object.
    * @param {!Function} ctor The constructor for the class to add the static
    *     method to.
    */
   function addSingletonGetter(ctor) {
     ctor.getInstance = function() {
       return ctor.instance_ || (ctor.instance_ = new ctor());
     };
   }

   /**
    * Creates a new event to be used with base.EventTarget or DOM EventTarget
    * objects.
    * @param {string} type The name of the event.
    * @param {boolean=} opt_bubbles Whether the event bubbles.
    *     Default is false.
    * @param {boolean=} opt_preventable Whether the default action of the event
    *     can be prevented.
    * @constructor
    * @extends {Event}
    */
   function Event(type, opt_bubbles, opt_preventable) {
     var e = base.doc.createEvent('Event');
     e.initEvent(type, !!opt_bubbles, !!opt_preventable);
     e.__proto__ = global.Event.prototype;
     return e;
   };

   /**
    * Initialization which must be deferred until run-time.
    */
   function initialize() {
     // If 'document' isn't defined, then we must be being pre-compiled,
     // so set a trap so that we're initialized on first access at run-time.
     if (!global.document) {
       var originalCr = cr;

       Object.defineProperty(global, 'cr', {
         get: function() {
           Object.defineProperty(global, 'cr', {value: originalCr});
           originalBase.initialize();
           return originalCr;
         },
         configurable: true
       });

       return;
     }

     Event.prototype = {__proto__: global.Event.prototype};

     base.doc = document;

     base.isMac = /Mac/.test(navigator.platform);
     base.isWindows = /Win/.test(navigator.platform);
     base.isChromeOS = /CrOS/.test(navigator.userAgent);
     base.isLinux = /Linux/.test(navigator.userAgent);
     base.isGTK = /GTK/.test(chrome.toolkit);
     base.isViews = /views/.test(chrome.toolkit);

     setModuleBasePath('/src');
   }

   return {
     set moduleBasePath(path) {
       setModuleBasePath(path);
     },

     get moduleBasePath() {
       return moduleBasePath;
     },

     require: require,
     requireStylesheet: requireStylesheet,
     exportTo: exportTo,

     addSingletonGetter: addSingletonGetter,
     createUid: createUid,
     defineProperty: defineProperty,
     dispatchPropertyChange: dispatchPropertyChange,
     dispatchSimpleEvent: dispatchSimpleEvent,
     Event: Event,
     getUid: getUid,
     initialize: initialize,
     PropertyKind: PropertyKind
   };
 })();


 /**
  * TODO(kgr): Move this to another file which is to be loaded last.
  * This will be done as part of future work to make this code pre-compilable.
  */
 base.initialize();
	// Copyright (c) 2012 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.

	'use strict';


	/**
	* The global object.
	* @type {!Object}
	* @const
	*/
	var global = this;


	/** Platform, package, object property, and Event support. */
	this.base = (function() {

	/**
	* Base path for modules. Used to form URLs for module 'require' requests.
	*/
	var moduleBasePath = '.';
	function setModuleBasePath(path) {
	if (path[path.length - 1] == '/')
	path = path.substring(0, path.length - 1);
	moduleBasePath = path;
	}


	function mLog(text, opt_indentLevel) {
	if (true)
	return;

	var spacing = '';
	var indentLevel = opt_indentLevel \|\| 0;
	for (var i = 0; i < indentLevel; i++)
	spacing += ' ';
	console.log(spacing + text);
	}

	/**
	* Builds an object structure for the provided namespace path,
	* ensuring that names that already exist are not overwritten. For
	* example:
	* 'a.b.c' -> a = {};a.b={};a.b.c={};
	* @param {string} name Name of the object that this file defines.
	* @param {*=} opt_object The object to expose at the end of the path.
	* @param {Object=} opt_objectToExportTo The object to add the path to;
	* default is {@code global}.
	* @private
	*/
	function exportPath(name, opt_object, opt_objectToExportTo) {
	var parts = name.split('.');
	var cur = opt_objectToExportTo \|\| global;

	for (var part; parts.length && (part = parts.shift());) {
	if (!parts.length && opt_object !== undefined) {
	// last part and we have an object; use it
	cur[part] = opt_object;
	} else if (part in cur) {
	cur = cur[part];
	} else {
	cur = cur[part] = {};
	}
	}
	return cur;
	};

	var didLoadModules = false;
	var moduleDependencies = {};
	var moduleStylesheets = {};

	function addModuleDependency(moduleName, dependentModuleName) {
	if (!moduleDependencies[moduleName])
	moduleDependencies[moduleName] = [];

	var dependentModules = moduleDependencies[moduleName];
	var found = false;
	for (var i = 0; i < dependentModules.length; i++)
	if (dependentModules[i] == dependentModuleName)
	found = true;
	if (!found)
	dependentModules.push(dependentModuleName);
	}

	function addModuleStylesheet(moduleName, stylesheetName) {
	if (!moduleStylesheets[moduleName])
	moduleStylesheets[moduleName] = [];

	var stylesheets = moduleStylesheets[moduleName];
	var found = false;
	for (var i = 0; i < stylesheets.length; i++)
	if (stylesheets[i] == stylesheetName)
	found = true;
	if (!found)
	stylesheets.push(stylesheetName);
	}

	function ensureDepsLoaded() {
	if (didLoadModules)
	return;
	didLoadModules = true;

	var req = new XMLHttpRequest();
	var src = moduleBasePath + '/' + 'deps.js';
	req.open('GET', src, false);
	req.send(null);
	if (req.status != 200)
	throw new Error('Could not find ' + deps +
	'. Run calcdeps.py and try again.');

	base.addModuleStylesheet = addModuleStylesheet;
	base.addModuleDependency = addModuleDependency;
	try {
	// By construction, the deps file should call addModuleDependency.
	eval(req.responseText);
	} catch (e) {
	throw new Error('When loading deps, got ' + e.stack ? e.stack : e);
	}
	delete base.addModuleDependency;
	delete base.addModuleStylesheet;
	}

	var moduleLoadStatus = {};
	function require(dependentModuleName, opt_indentLevel) {
	var indentLevel = opt_indentLevel \|\| 0;

	if (window.FLATTENED) {
	if (!window.FLATTENED[dependentModuleName])
	throw new Error('Somehow, module ' + dependentModuleName +
	' didn\'t get flattened!');
	return;
	}
	ensureDepsLoaded();

	mLog('require(' + dependentModuleName + ')', indentLevel);

	if (moduleLoadStatus[dependentModuleName] == 'APPENDED')
	return;
	if (moduleLoadStatus[dependentModuleName] == 'RESOLVING')
	throw new Error('Circular dependency betwen modules. Cannot continue!');
	moduleLoadStatus[dependentModuleName] = 'RESOLVING';

	// Load the module stylesheet first.
	var stylesheets = moduleStylesheets[dependentModuleName] \|\| [];
	for (var i = 0; i < stylesheets.length; i++)
	requireStylesheet(stylesheets[i]);

	// Load the module's dependent scripts after.
	var dependentModules =
	moduleDependencies[dependentModuleName] \|\| [];
	for (var i = 0; i < dependentModules.length; i++)
	require(dependentModules[i], indentLevel + 1);

	mLog('load(' + dependentModuleName + ')', indentLevel);
	// Load the module itself.
	var localPath = dependentModuleName.replace(/\./g, '/') + '.js';
	var src = moduleBasePath + '/' + localPath;
	var text = '<script type="text/javascript" src="' + src +
	'"></' + 'script>';
	base.doc.write(text);
	moduleLoadStatus[dependentModuleName] = 'APPENDED';
	}

	var stylesheetLoadStatus = {};
	function requireStylesheet(dependentStylesheetName) {
	if (window.FLATTENED)
	return;

	if (stylesheetLoadStatus[dependentStylesheetName])
	return;
	stylesheetLoadStatus[dependentStylesheetName] = true;
	var localPath = dependentStylesheetName.replace(/\./g, '/') + '.css';
	var stylesheetPath = moduleBasePath + '/' + localPath;

	var linkEl = document.createElement('link');
	linkEl.setAttribute('rel', 'stylesheet');
	linkEl.setAttribute('href', stylesheetPath);
	base.doc.head.appendChild(linkEl);
	}

	function exportTo(namespace, fn) {
	var obj = exportPath(namespace);
	try {
	var exports = fn();
	} catch (e) {
	console.log('While running exports for ', name, ':');
	console.log(e.stack \|\| e);
	return;
	}

	for (var propertyName in exports) {
	// Maybe we should check the prototype chain here? The current usage
	// pattern is always using an object literal so we only care about own
	// properties.
	var propertyDescriptor = Object.getOwnPropertyDescriptor(exports,
	propertyName);
	if (propertyDescriptor) {
	Object.defineProperty(obj, propertyName, propertyDescriptor);
	mLog(' +' + propertyName);
	}
	}
	};

	/**
	* Fires a property change event on the target.
	* @param {EventTarget} target The target to dispatch the event on.
	* @param {string} propertyName The name of the property that changed.
	* @param {*} newValue The new value for the property.
	* @param {*} oldValue The old value for the property.
	*/
	function dispatchPropertyChange(target, propertyName, newValue, oldValue) {
	var e = new base.Event(propertyName + 'Change');
	e.propertyName = propertyName;
	e.newValue = newValue;
	e.oldValue = oldValue;
	target.dispatchEvent(e);
	}

	/**
	* Converts a camelCase javascript property name to a hyphenated-lower-case
	* attribute name.
	* @param {string} jsName The javascript camelCase property name.
	* @return {string} The equivalent hyphenated-lower-case attribute name.
	*/
	function getAttributeName(jsName) {
	return jsName.replace(/([A-Z])/g, '-$1').toLowerCase();
	}

	/**
	* The kind of property to define in {@code defineProperty}.
	* @enum {number}
	* @const
	*/
	var PropertyKind = {
	/**
	* Plain old JS property where the backing data is stored as a 'private'
	* field on the object.
	*/
	JS: 'js',

	/**
	* The property backing data is stored as an attribute on an element.
	*/
	ATTR: 'attr',

	/**
	* The property backing data is stored as an attribute on an element. If the
	* element has the attribute then the value is true.
	*/
	BOOL_ATTR: 'boolAttr'
	};

	/**
	* Helper function for defineProperty that returns the getter to use for the
	* property.
	* @param {string} name The name of the property.
	* @param {base.PropertyKind} kind The kind of the property.
	* @return {function():*} The getter for the property.
	*/
	function getGetter(name, kind) {
	switch (kind) {
	case PropertyKind.JS:
	var privateName = name + '_';
	return function() {
	return this[privateName];
	};
	case PropertyKind.ATTR:
	var attributeName = getAttributeName(name);
	return function() {
	return this.getAttribute(attributeName);
	};
	case PropertyKind.BOOL_ATTR:
	var attributeName = getAttributeName(name);
	return function() {
	return this.hasAttribute(attributeName);
	};
	}
	}

	/**
	* Helper function for defineProperty that returns the setter of the right
	* kind.
	* @param {string} name The name of the property we are defining the setter
	* for.
	* @param {base.PropertyKind} kind The kind of property we are getting the
	* setter for.
	* @param {function(*):void} opt_setHook A function to run after the property
	* is set, but before the propertyChange event is fired.
	* @return {function(*):void} The function to use as a setter.
	*/
	function getSetter(name, kind, opt_setHook) {
	switch (kind) {
	case PropertyKind.JS:
	var privateName = name + '_';
	return function(value) {
	var oldValue = this[privateName];
	if (value !== oldValue) {
	this[privateName] = value;
	if (opt_setHook)
	opt_setHook.call(this, value, oldValue);
	dispatchPropertyChange(this, name, value, oldValue);
	}
	};

	case PropertyKind.ATTR:
	var attributeName = getAttributeName(name);
	return function(value) {
	var oldValue = this[attributeName];
	if (value !== oldValue) {
	if (value == undefined)
	this.removeAttribute(attributeName);
	else
	this.setAttribute(attributeName, value);
	if (opt_setHook)
	opt_setHook.call(this, value, oldValue);
	dispatchPropertyChange(this, name, value, oldValue);
	}
	};

	case PropertyKind.BOOL_ATTR:
	var attributeName = getAttributeName(name);
	return function(value) {
	var oldValue = this[attributeName];
	if (value !== oldValue) {
	if (value)
	this.setAttribute(attributeName, name);
	else
	this.removeAttribute(attributeName);
	if (opt_setHook)
	opt_setHook.call(this, value, oldValue);
	dispatchPropertyChange(this, name, value, oldValue);
	}
	};
	}
	}

	/**
	* Defines a property on an object. When the setter changes the value a
	* property change event with the type {@code name + 'Change'} is fired.
	* @param {!Object} obj The object to define the property for.
	* @param {string} name The name of the property.
	* @param {base.PropertyKind=} opt_kind What kind of underlying storage to
	* use.
	* @param {function(*):void} opt_setHook A function to run after the
	* property is set, but before the propertyChange event is fired.
	*/
	function defineProperty(obj, name, opt_kind, opt_setHook) {
	if (typeof obj == 'function')
	obj = obj.prototype;

	var kind = opt_kind \|\| PropertyKind.JS;

	if (!obj.__lookupGetter__(name))
	obj.__defineGetter__(name, getGetter(name, kind));

	if (!obj.__lookupSetter__(name))
	obj.__defineSetter__(name, getSetter(name, kind, opt_setHook));
	}

	/**
	* Counter for use with createUid
	*/
	var uidCounter = 1;

	/**
	* @return {number} A new unique ID.
	*/
	function createUid() {
	return uidCounter++;
	}

	/**
	* Returns a unique ID for the item. This mutates the item so it needs to be
	* an object
	* @param {!Object} item The item to get the unique ID for.
	* @return {number} The unique ID for the item.
	*/
	function getUid(item) {
	if (item.hasOwnProperty('uid'))
	return item.uid;
	return item.uid = createUid();
	}

	/**
	* Dispatches a simple event on an event target.
	* @param {!EventTarget} target The event target to dispatch the event on.
	* @param {string} type The type of the event.
	* @param {boolean=} opt_bubbles Whether the event bubbles or not.
	* @param {boolean=} opt_cancelable Whether the default action of the event
	* can be prevented.
	* @return {boolean} If any of the listeners called {@code preventDefault}
	* during the dispatch this will return false.
	*/
	function dispatchSimpleEvent(target, type, opt_bubbles, opt_cancelable) {
	var e = new base.Event(type, opt_bubbles, opt_cancelable);
	return target.dispatchEvent(e);
	}

	/**
	* Adds a {@code getInstance} static method that always return the same
	* instance object.
	* @param {!Function} ctor The constructor for the class to add the static
	* method to.
	*/
	function addSingletonGetter(ctor) {
	ctor.getInstance = function() {
	return ctor.instance_ \|\| (ctor.instance_ = new ctor());
	};
	}

	/**
	* Creates a new event to be used with base.EventTarget or DOM EventTarget
	* objects.
	* @param {string} type The name of the event.
	* @param {boolean=} opt_bubbles Whether the event bubbles.
	* Default is false.
	* @param {boolean=} opt_preventable Whether the default action of the event
	* can be prevented.
	* @constructor
	* @extends {Event}
	*/
	function Event(type, opt_bubbles, opt_preventable) {
	var e = base.doc.createEvent('Event');
	e.initEvent(type, !!opt_bubbles, !!opt_preventable);
	e.__proto__ = global.Event.prototype;
	return e;
	};

	/**
	* Initialization which must be deferred until run-time.
	*/
	function initialize() {
	// If 'document' isn't defined, then we must be being pre-compiled,
	// so set a trap so that we're initialized on first access at run-time.
	if (!global.document) {
	var originalCr = cr;

	Object.defineProperty(global, 'cr', {
	get: function() {
	Object.defineProperty(global, 'cr', {value: originalCr});
	originalBase.initialize();
	return originalCr;
	},
	configurable: true
	});

	return;
	}

	Event.prototype = {__proto__: global.Event.prototype};

	base.doc = document;

	base.isMac = /Mac/.test(navigator.platform);
	base.isWindows = /Win/.test(navigator.platform);
	base.isChromeOS = /CrOS/.test(navigator.userAgent);
	base.isLinux = /Linux/.test(navigator.userAgent);
	base.isGTK = /GTK/.test(chrome.toolkit);
	base.isViews = /views/.test(chrome.toolkit);

	setModuleBasePath('/src');
	}

	return {
	set moduleBasePath(path) {
	setModuleBasePath(path);
	},

	get moduleBasePath() {
	return moduleBasePath;
	},

	require: require,
	requireStylesheet: requireStylesheet,
	exportTo: exportTo,

	addSingletonGetter: addSingletonGetter,
	createUid: createUid,
	defineProperty: defineProperty,
	dispatchPropertyChange: dispatchPropertyChange,
	dispatchSimpleEvent: dispatchSimpleEvent,
	Event: Event,
	getUid: getUid,
	initialize: initialize,
	PropertyKind: PropertyKind
	};
	})();


	/**
	* TODO(kgr): Move this to another file which is to be loaded last.
	* This will be done as part of future work to make this code pre-compilable.
	*/
	base.initialize();