ServiceWorker: Confirm the liveness of the associated context before handling message

content/browser/service_worker/service_worker_provider_host_registry.h

+// Copyright 2014 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.
+
+#ifndef CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_PROVIDER_HOST_REGISTRY_H_
+#define CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_PROVIDER_HOST_REGISTRY_H_
+
+#include "base/id_map.h"
+#include "base/memory/scoped_ptr.h"
+#include "content/common/content_export.h"
+
+namespace content {
+
+class ServiceWorkerProviderHost;
+
+class CONTENT_EXPORT ServiceWorkerProviderHostRegistry {
+ public:
+  typedef IDMap<ServiceWorkerProviderHost, IDMapOwnPointer> ProviderMap;
+  typedef IDMap<ProviderMap, IDMapOwnPointer> ProcessToProviderMap;
+
+  // Iterates over ServiceWorkerProviderHost objects in a ProcessToProviderMap.
+  class Iterator {
+   public:
+    ~Iterator();
+    ServiceWorkerProviderHost* GetProviderHost();
+    void Advance();
+    bool IsAtEnd();
+
+   private:
+    friend class ServiceWorkerProviderHostRegistry;
+    explicit Iterator(ProcessToProviderMap* map);
+    void Initialize();
+
+    ProcessToProviderMap* map_;
+    scoped_ptr<ProcessToProviderMap::iterator> provider_iterator_;
+    scoped_ptr<ProviderMap::iterator> provider_host_iterator_;
+
+    DISALLOW_COPY_AND_ASSIGN(Iterator);
+  };
+
+  ServiceWorkerProviderHostRegistry();
+  virtual ~ServiceWorkerProviderHostRegistry();
+
+  ServiceWorkerProviderHost* GetProviderHost(int process_id, int provider_id);
+  void AddProviderHost(scoped_ptr<ServiceWorkerProviderHost> provider_host);
+  void RemoveProviderHost(int process_id, int provider_id);
+  void RemoveAllProviderHostsForProcess(int process_id);
+  scoped_ptr<Iterator> GetProviderHostIterator();
+
+ private:
+  ProviderMap* GetProviderMapForProcess(int process_id) {
+    return providers_.Lookup(process_id);
+  }
+
+  ProcessToProviderMap providers_;
+
+  DISALLOW_COPY_AND_ASSIGN(ServiceWorkerProviderHostRegistry);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_PROVIDER_HOST_REGISTRY_H_