Cache the Windows Parental Controls Platform Answer

chrome/browser/prefs/incognito_mode_prefs.cc

Index: chrome/browser/prefs/incognito_mode_prefs.cc
diff --git a/chrome/browser/prefs/incognito_mode_prefs.cc b/chrome/browser/prefs/incognito_mode_prefs.cc
index e0255d4947d11a90c3d2e5fbbd56f707459c811b..1821ceb0174e64d67a54c0074f6d4e7bc5136ccb 100644
--- a/chrome/browser/prefs/incognito_mode_prefs.cc
+++ b/chrome/browser/prefs/incognito_mode_prefs.cc
@@ -23,7 +23,17 @@
 #if defined(OS_WIN)
 namespace {
 
-bool g_parental_control_on = false;
+// Possible values for the parental controls state.
+enum class ParentalControlsState {
+  // Parental controls state unknown. We have not queried for this value yet.
+  UNKNOWN = 0,
+  // Parental controls activity logging disabled.
+  ACTIVITY_LOGGING_DISABLED = 1,
+  // Parental controls activity logging enabled.
+  ACTIVITY_LOGGING_ENABLED = 2,
+};
+ParentalControlsState g_parental_controls_state =
+    ParentalControlsState::UNKNOWN;
 
 } // empty namespace
 #endif  // OS_WIN
@@ -47,7 +57,7 @@ IncognitoModePrefs::Availability IncognitoModePrefs::GetAvailability(
   Availability result = IncognitoModePrefs::ENABLED;
   bool valid = IntToAvailability(pref_value, &result);
   DCHECK(valid);
-  if (ArePlatformParentalControlsEnabled()) {
+  if (ArePlatformParentalControlsEnabledCached()) {
     if (result == IncognitoModePrefs::FORCED)
       LOG(ERROR) << "Ignoring FORCED incognito. Parental control logging on";
     return IncognitoModePrefs::DISABLED;
@@ -101,28 +111,20 @@ bool IncognitoModePrefs::CanOpenBrowser(Profile* profile) {
   }
 }
 
-// static
-bool IncognitoModePrefs::ArePlatformParentalControlsEnabled() {
-#if defined(OS_WIN)
-  // Disable incognito mode windows if parental controls are on. This is only
-  // for Windows Vista and above.
-  return base::win::IsParentalControlActivityLoggingOn();
-#elif defined(OS_ANDROID)
-  return chrome::android::ChromiumApplication::AreParentalControlsEnabled();
-#else
-  return false;
-#endif
-}
-
 #if defined(OS_WIN)
 void IncognitoModePrefs::InitializePlatformParentalControls() {

[msw, 2015/02/27 02:08:28]

Define this on all platforms and just do platform-specific work internally, like
ArePlatformParentalControlsEnabledCached. Then remove ifdefs from clients.

[robliao, 2015/02/27 02:14:02]

Agreed with this at this point. The change started out isolated and was platform
specific for the init. This will be in the next change.

-  g_parental_control_on = base::win::IsParentalControlActivityLoggingOn();
+  g_parental_controls_state =
+      base::win::IsParentalControlActivityLoggingOn() ?
+          ParentalControlsState::ACTIVITY_LOGGING_ENABLED :
+          ParentalControlsState::ACTIVITY_LOGGING_DISABLED;
 }
 #endif // OS_WIN
 
 bool IncognitoModePrefs::ArePlatformParentalControlsEnabledCached() {
 #if defined(OS_WIN)
-  return g_parental_control_on;
+  DCHECK(g_parental_controls_state != ParentalControlsState::UNKNOWN);
+  return g_parental_controls_state ==
+      ParentalControlsState::ACTIVITY_LOGGING_ENABLED;
 #elif defined(OS_ANDROID)
   return chrome::android::ChromiumApplication::AreParentalControlsEnabled();
 #else