Disable Web Notifications in Incognito

components/content_settings/core/browser/content_settings_info.h

Index: components/content_settings/core/browser/content_settings_info.h
diff --git a/components/content_settings/core/browser/content_settings_info.h b/components/content_settings/core/browser/content_settings_info.h
index b7018dfff5209db38fb0b1c92d812f998764edfe..f6c8f96a573298f0c3e89be54d01ff71eeab61e8 100644
--- a/components/content_settings/core/browser/content_settings_info.h
+++ b/components/content_settings/core/browser/content_settings_info.h
@@ -23,10 +23,15 @@ class ContentSettingsInfo {
     // as usual.
     INHERIT_IN_INCOGNITO,
 
-    // Content setting will only partially inherit from regular to incognito
-    // profiles: BLOCK will inherit as usual, but ALLOW will become ASK.
-    // This is unusual, so seek privacy review before using this.
-    INHERIT_IN_INCOGNITO_EXCEPT_ALLOW
+    // Content setting is disallowed in incognito. However, to prevent sites
+    // from using this setting to detect whether incognito mode is active, the
+    // actual behavior is more subtle. The content setting will only partially
+    // inherit from regular to incognito profiles: BLOCK will inherit as usual,
+    // but ALLOW will become ASK. Only once the website actually requests the
+    // permission, will it then be automatically denied after a random time
+    // delay (simulating a user clicking a bubble/infobar). This is unusual, so
+    // seek privacy review before using this.
+    DENY_IN_INCOGNITO_AFTER_DELAY

[raymes, 2016/01/12 06:00:41]

Now that I think about it, could we instead remove the part about the delay from
the name here? That part seems more specific to PermissionContext and if we have
the special logic in a subclass of PermissionContext, we might be able to leave
this named as INHERIT_IN_INCOGNITO_EXCEPT_ALLOW. wdyt?

[johnme, 2016/01/12 18:04:52]

Done. I've moved the main behavior to a simple override of
NotificationPermissionContext::DecidePermission, and a check in the
PermissionMenuModel constructor. So now this content settings layer enum only
controls the inheritance part. Mounir also agreed that this was cleaner.

   };
 
   // This object does not take ownership of |website_settings_info|.