Fixes and improvements to cloud policy for extensions.

components/policy/core/common/schema_registry.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/policy/core/common/schema_registry.h"
 
 #include "base/logging.h"
 
 namespace policy {
 
@@ skipping 11 matching lines @@
 
 void SchemaRegistry::RegisterComponent(const PolicyNamespace& ns,
                                        const Schema& schema) {
   ComponentMap map;
   map[ns.component_id] = schema;
   RegisterComponents(ns.domain, map);
 }
 
 void SchemaRegistry::RegisterComponents(PolicyDomain domain,
                                         const ComponentMap& components) {
+  // Don't issue notifications if nothing is being registered.
+  if (components.empty())
+    return;
   // Assume that a schema was updated if the namespace was already registered
   // before.
   DomainMap map(schema_map_->GetDomains());
   for (ComponentMap::const_iterator it = components.begin();
        it != components.end(); ++it) {
     map[domain][it->first] = it->second;
   }
   schema_map_ = new SchemaMap(map);
   Notify(true);
 }
@@ skipping 124 matching lines @@
            comp_it != reg_component_map.end(); ++comp_it) {
         map[domain_it->first][comp_it->first] = comp_it->second;
       }
     }
   }
   schema_map_ = new SchemaMap(map);
   Notify(has_new_schemas);
 }
 
 }  // namespace policy