Add a "guard" content settings type for chooser permissions.

chrome/browser/permissions/chooser_context_base.cc

Index: chrome/browser/permissions/chooser_context_base.cc
diff --git a/chrome/browser/permissions/chooser_context_base.cc b/chrome/browser/permissions/chooser_context_base.cc
index 22f043efe2e238bf7cba6854b1959bf9e9151359..ac9ea921bc6056d733d192aa133f129f948ca4b0 100644
--- a/chrome/browser/permissions/chooser_context_base.cc
+++ b/chrome/browser/permissions/chooser_context_base.cc
@@ -16,17 +16,32 @@ const char kObjectListKey[] = "chosen-objects";
 
 ChooserContextBase::ChooserContextBase(
     Profile* profile,
+    const ContentSettingsType guard_content_settings_type,
     const ContentSettingsType data_content_settings_type)
     : host_content_settings_map_(
           HostContentSettingsMapFactory::GetForProfile(profile)),
+      guard_content_settings_type_(guard_content_settings_type),
       data_content_settings_type_(data_content_settings_type) {
   DCHECK(host_content_settings_map_);
 }
 
 ChooserContextBase::~ChooserContextBase() {}
 
+bool ChooserContextBase::CanRequestObjectPermission(
+    const GURL& requesting_origin,
+    const GURL& embedding_origin) {
+  ContentSetting content_setting =
+      host_content_settings_map_->GetContentSetting(
+          requesting_origin, embedding_origin, guard_content_settings_type_,
+          std::string());
+  return content_setting == CONTENT_SETTING_ALLOW;
+}
+
 ObjectList ChooserContextBase::GetGrantedObjects(const GURL& requesting_origin,
                                                  const GURL& embedding_origin) {
+  if (!CanRequestObjectPermission(requesting_origin, embedding_origin))
+    return ObjectList();
+
   scoped_ptr<base::DictionaryValue> setting =
       GetWebsiteSetting(requesting_origin, embedding_origin);
   scoped_ptr<base::Value> objects;
@@ -57,7 +72,9 @@ void ChooserContextBase::GrantObjectPermission(
     const GURL& requesting_origin,
     const GURL& embedding_origin,
     scoped_ptr<base::DictionaryValue> object) {
-  DCHECK(object && IsValidObject(*object));
+  DCHECK(object);
+  DCHECK(IsValidObject(*object));
+  DCHECK(CanRequestObjectPermission(requesting_origin, embedding_origin));
   scoped_ptr<base::DictionaryValue> setting =
       GetWebsiteSetting(requesting_origin, embedding_origin);
   base::ListValue* object_list;