Add missing (and remove superfluous) 'explicit' from constructors.

chrome/common/extensions/permissions/api_permission_set.h

Index: chrome/common/extensions/permissions/api_permission_set.h
diff --git a/chrome/common/extensions/permissions/api_permission_set.h b/chrome/common/extensions/permissions/api_permission_set.h
index 848484e2399720713194ac6ec2ec09a5654e7cc6..5c993696f037608595539fc4af5e99c84abf7698 100644
--- a/chrome/common/extensions/permissions/api_permission_set.h
+++ b/chrome/common/extensions/permissions/api_permission_set.h
@@ -27,7 +27,7 @@ class APIPermissionSet {
   class const_iterator :
     public std::iterator<std::input_iterator_tag, const APIPermission*> {
    public:
-    const_iterator(const APIPermissionMap::const_iterator& it);
+    explicit const_iterator(const APIPermissionMap::const_iterator& it);
     const_iterator(const const_iterator& ids_it);
 
     const_iterator& operator++() {
@@ -71,11 +71,11 @@ class APIPermissionSet {
   }
 
   const_iterator end() const {
-    return map().end();
+    return const_iterator(map().end());
   }
 
   const_iterator find(APIPermission::ID id) const {
-    return map().find(id);
+    return const_iterator(map().find(id));
   }
 
   const APIPermissionMap& map() const {