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

Source/devtools/front_end/common/Platform.js

Index: Source/devtools/front_end/common/Platform.js
diff --git a/Source/devtools/front_end/common/Platform.js b/Source/devtools/front_end/common/Platform.js
index b16f20840b13b5f382c2f6b8032a6374892355ed..5e11b7943068e26b0e1645805c89b5ff70fcb896 100644
--- a/Source/devtools/front_end/common/Platform.js
+++ b/Source/devtools/front_end/common/Platform.js
@@ -26,6 +26,9 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+/**
+ * @return {string}
+ */
 WebInspector.platform = function()
 {
     if (!WebInspector._platform)
@@ -33,6 +36,9 @@ WebInspector.platform = function()
     return WebInspector._platform;
 }
 
+/**
+ * @return {boolean}
+ */
 WebInspector.isMac = function()
 {
     if (typeof WebInspector._isMac === "undefined")
@@ -41,6 +47,9 @@ WebInspector.isMac = function()
     return WebInspector._isMac;
 }
 
+/**
+ * @return {boolean}
+ */
 WebInspector.isWin = function()
 {
     if (typeof WebInspector._isWin === "undefined")
@@ -57,6 +66,9 @@ WebInspector.PlatformFlavor = {
     MacLion: "mac-lion"
 }
 
+/**
+ * @return {string}
+ */
 WebInspector.platformFlavor = function()
 {
     function detectFlavor()
@@ -95,6 +107,9 @@ WebInspector.platformFlavor = function()
     return WebInspector._platformFlavor;
 }
 
+/**
+ * @return {string}
+ */
 WebInspector.port = function()
 {
     if (!WebInspector._port)