DevTools: Add JSDoc for static methods, fix JSDoc types and induced errors

Source/devtools/front_end/common/Platform.js

 /*
  * Copyright (C) 2014 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:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
  *     documentation and/or other materials provided with the distribution.
  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
  *     its contributors may be used to endorse or promote products derived
  *     from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+/**
+ * @return {string}
+ */
 WebInspector.platform = function()
 {
     if (!WebInspector._platform)
         WebInspector._platform = InspectorFrontendHost.platform();
     return WebInspector._platform;
 }
 
+/**
+ * @return {boolean}
+ */
 WebInspector.isMac = function()
 {
     if (typeof WebInspector._isMac === "undefined")
         WebInspector._isMac = WebInspector.platform() === "mac";
 
     return WebInspector._isMac;
 }
 
+/**
+ * @return {boolean}
+ */
 WebInspector.isWin = function()
 {
     if (typeof WebInspector._isWin === "undefined")
         WebInspector._isWin = WebInspector.platform() === "windows";
 
     return WebInspector._isWin;
 }
 
 WebInspector.PlatformFlavor = {
     WindowsVista: "windows-vista",
     MacTiger: "mac-tiger",
     MacLeopard: "mac-leopard",
     MacSnowLeopard: "mac-snowleopard",
     MacLion: "mac-lion"
 }
 
+/**
+ * @return {string}
+ */
 WebInspector.platformFlavor = function()
 {
     function detectFlavor()
     {
         const userAgent = navigator.userAgent;
 
         if (WebInspector.platform() === "windows") {
             var match = userAgent.match(/Windows NT (\d+)\.(?:\d+)/);
             if (match && match[1] >= 6)
                 return WebInspector.PlatformFlavor.WindowsVista;
@@ skipping 18 matching lines @@
             }
         }
     }
 
     if (!WebInspector._platformFlavor)
         WebInspector._platformFlavor = detectFlavor();
 
     return WebInspector._platformFlavor;
 }
 
+/**
+ * @return {string}
+ */
 WebInspector.port = function()
 {
     if (!WebInspector._port)
         WebInspector._port = InspectorFrontendHost.port();
 
     return WebInspector._port;
 }
 
 /**
  * @return {string}
@@ skipping 29 matching lines @@
         break;
     case "mac":
         WebInspector._monospaceFontFamily = "Menlo, monospace";
         break;
     case "windows":
         WebInspector._monospaceFontFamily = "Consolas, monospace";
         break;
     }
     return WebInspector._monospaceFontFamily;
 }