Ensure settings returned from Content Settings providers are valid

components/content_settings/core/browser/content_settings_pref.cc

Index: components/content_settings/core/browser/content_settings_pref.cc
diff --git a/components/content_settings/core/browser/content_settings_pref.cc b/components/content_settings/core/browser/content_settings_pref.cc
index f32e3018b4cc0828d4b5b7efa7a596d5f022d82b..514c4c718fb9726355a2bff60c10a7bceb2fbafb 100644
--- a/components/content_settings/core/browser/content_settings_pref.cc
+++ b/components/content_settings/core/browser/content_settings_pref.cc
@@ -253,6 +253,7 @@ void ContentSettingsPref::ReadContentSettingsFromPref() {
           DCHECK(is_integer);
           DCHECK_NE(CONTENT_SETTING_DEFAULT, setting);
           std::unique_ptr<base::Value> setting_ptr(new base::Value(setting));
+          DCHECK(IsValueAllowedForType(setting_ptr.get(), content_type_));

[msramek, 2017/05/03 20:05:42]

I'm slightly uncomfortable about this, since the user could technically edit the
Preferences file; but then again, the same is true of other preferences as well.

I can also see myself tripping on this the next time I write some migration code
and switch to another git branch.

[raymes, 2017/05/04 05:49:15]

I agree - it could just be an annoyance. But we were already doing this check
below for the non-resource identifier case and it hasn't caused any trouble yet.
I'll leave it for now and we can remove them both if it's problematic :)

           value_map_.SetValue(pattern_pair.first,
                               pattern_pair.second,
                               content_type_,