<webview>: Add support for filtering extension events by instanceId.

extensions/common/event_matcher.cc

 // Copyright (c) 2012 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 "extensions/common/event_matcher.h"
 
 #include "extensions/common/event_filtering_info.h"
 
 namespace {
 const char kUrlFiltersKey[] = "url";
 }
 
 namespace extensions {
 
 EventMatcher::EventMatcher(scoped_ptr<base::DictionaryValue> filter)
     : filter_(filter.Pass()) {
 }
 
 EventMatcher::~EventMatcher() {
 }
 
 bool EventMatcher::MatchNonURLCriteria(
     const EventFilteringInfo& event_info) const {
-  // There is currently no criteria apart from URL criteria.
-  return true;
+  if (!event_info.has_instance_id())
+    return true;
+  return event_info.instance_id() == GetInstanceID();
 }
 
 int EventMatcher::GetURLFilterCount() const {
   base::ListValue* url_filters = NULL;
   if (filter_->GetList(kUrlFiltersKey, &url_filters))
     return url_filters->GetSize();
   return 0;
 }
 
 bool EventMatcher::GetURLFilter(int i, base::DictionaryValue** url_filter_out) {
   base::ListValue* url_filters = NULL;
   if (filter_->GetList(kUrlFiltersKey, &url_filters)) {
     return url_filters->GetDictionary(i, url_filter_out);
   }
   return false;
 }
 
 int EventMatcher::HasURLFilters() const {
   return GetURLFilterCount() != 0;
 }
 
+int EventMatcher::GetInstanceID() const {
+  int instance_id = 0;
+  filter_->GetInteger("instanceId", &instance_id);
+  return instance_id;
+}
+
 }  // namespace extensions