Cache the Windows Parental Controls Platform Answer

chrome/browser/prefs/incognito_mode_prefs.h

Index: chrome/browser/prefs/incognito_mode_prefs.h
diff --git a/chrome/browser/prefs/incognito_mode_prefs.h b/chrome/browser/prefs/incognito_mode_prefs.h
index 0837cb43e452a2f2475d3a70a5b364705a6041ae..4f0911bb97c30b0b0b76759642b6d9a0bfe59645 100644
--- a/chrome/browser/prefs/incognito_mode_prefs.h
+++ b/chrome/browser/prefs/incognito_mode_prefs.h
@@ -68,16 +68,18 @@ class IncognitoModePrefs {
   // be called on any thread.
   static bool ArePlatformParentalControlsEnabledCached();
 
-#if defined(OS_WIN)
   // Initializes the parental control settings. Must be called on UI thread and
   // before |ArePlatformParentalControlsEnabled|.
   static void InitializePlatformParentalControls();
-#endif // OS_WIN
+
+#if defined(UNIT_TEST)
+  static void UninitializePlatformParentalControls() {
+    UninitializePlatformParentalControlsImpl();
+  }
+#endif  // defined(UNIT_TEST)
 
  private:
-  // Returns whether parental controls have been enabled on the platform, which
-  // if enabled will overrule the Availability as configured in prefs.
-  static bool ArePlatformParentalControlsEnabled();
+  static void UninitializePlatformParentalControlsImpl();
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(IncognitoModePrefs);
 };