Ensure content settings aren't persisted in the guest profile

components/content_settings/core/browser/host_content_settings_map.cc

Index: components/content_settings/core/browser/host_content_settings_map.cc
diff --git a/components/content_settings/core/browser/host_content_settings_map.cc b/components/content_settings/core/browser/host_content_settings_map.cc
index 35100454fee7ba4ca79122721f164677a47a97a2..015bd97272633ca5165a1cc751a6b4220abbb52d 100644
--- a/components/content_settings/core/browser/host_content_settings_map.cc
+++ b/components/content_settings/core/browser/host_content_settings_map.cc
@@ -94,25 +94,32 @@ scoped_ptr<base::Value> CoerceSettingInheritedToIncognito(
 }  // namespace
 
 HostContentSettingsMap::HostContentSettingsMap(PrefService* prefs,
-                                               bool incognito)
+                                               bool is_incognito_profile,
+                                               bool is_guest_profile)
     :
 #ifndef NDEBUG
       used_from_thread_id_(base::PlatformThread::CurrentId()),
 #endif
       prefs_(prefs),
-      is_off_the_record_(incognito) {
+      is_off_the_record_(is_incognito_profile || is_guest_profile) {
+  DCHECK(!(is_incognito_profile && is_guest_profile));
   content_settings::ObservableProvider* policy_provider =
       new content_settings::PolicyProvider(prefs_);
   policy_provider->AddObserver(this);
   content_settings_providers_[POLICY_PROVIDER] = policy_provider;
 
-  content_settings::ObservableProvider* pref_provider =
+  content_settings::PrefProvider* pref_provider =
       new content_settings::PrefProvider(prefs_, is_off_the_record_);
   pref_provider->AddObserver(this);
   content_settings_providers_[PREF_PROVIDER] = pref_provider;
+  // This ensures that content settings are cleraed for the guest profile. This

[msramek, 2016/01/19 13:35:07]

nit: cleared

[raymes, 2016/01/19 23:31:39]

Done.

+  // wouldn't be needed except that we used to allow settings to be stored for
+  // the guest profile and so we need to ensure those get cleared.
+  if (is_guest_profile)
+    pref_provider->ClearPrefs();
 
   content_settings::ObservableProvider* default_provider =
-      new content_settings::DefaultProvider(prefs_, is_off_the_record_);
+      new content_settings::DefaultProvider(prefs_, is_incognito_profile);

[msramek, 2016/01/19 13:35:07]

This should be |is_off_the_record_| (which will allow us to simplify the
constructor back to using just one boolean).

In the guest profile, it holds that |is_incognito_profile| == false, so here we
instantiate a regular DefaultProvider that writes into the pref. This means that
the default setting persists between guest sessions, which is not desired.

Note that in chrome://settings, most settings are hidden, which means that the
guest user should not touch them - and therefore, neither should
DefaultProvider.

Apparently it is possible to access chrome://settings/content directly by typing
the link, but that is a bug. I filed crbug.com/579052.

[raymes, 2016/01/19 23:31:39]

Ok - that sounds good. I wasn't sure of the better approach but this makes sense
to me.

I still need both bools in the constructor - see the line above which clears the
prefs only for a guest profile. If we do this in incognito we will delete the
underlying (inherited) prefs in the users profile.

[msramek, 2016/01/20 11:01:45]

Acknowledged.

   default_provider->AddObserver(this);
   content_settings_providers_[DEFAULT_PROVIDER] = default_provider;
 }