Declarative content scripts: Browser-side: per-extension shared memory regions (lazily loaded)

chrome/browser/extensions/declarative_user_script_master.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 CHROME_BROWSER_EXTENSIONS_DECLARATIVE_USER_SCRIPT_MASTER_H_
+#define CHROME_BROWSER_EXTENSIONS_DECLARATIVE_USER_SCRIPT_MASTER_H_
+
+#include "base/scoped_observer.h"
+#include "chrome/browser/extensions/user_script_loader.h"
+#include "extensions/browser/extension_registry_observer.h"
+#include "extensions/common/extension.h"
+
+class Profile;
+
+namespace extensions {
+
+class ExtensionRegistry;
+class UserScript;
+
+// Manages declarative user scripts for a single extension. Owns a
+// UserScriptLoader to which file loading and shared memory management
+// operations are delegated, and provides an interface for adding, removing,
+// and clearing scripts.
+class DeclarativeUserScriptMaster : public ExtensionRegistryObserver {
+ public:
+  DeclarativeUserScriptMaster(Profile* profile,
+                              const ExtensionId& extension_id);
+  virtual ~DeclarativeUserScriptMaster();
+
+  // Adds script to shared memory region. This may not happen right away if a
+  // script load is in progress.
+  void AddScript(const UserScript& script);
+
+  // Removes script from shared memory region. This may not happen right away if
+  // a script load is in progress.
+  void RemoveScript(const UserScript& script);
+
+  // Removes all scripts from shared memory region. This may not happen right
+  // away if a script load is in progress.
+  void ClearScripts();
+
+  const ExtensionId& extension_id() const { return extension_id_; }
+
+ private:
+  // ExtensionRegistryObserver implementation.
+  virtual void OnExtensionUnloaded(
+      content::BrowserContext* browser_context,
+      const Extension* extension,
+      UnloadedExtensionInfo::Reason reason) OVERRIDE;
+
+  // ID of extension that owns scripts that this component manages.
+  ExtensionId extension_id_;
+
+  // Script loader that handles loading contents of scripts into shared memory
+  // and notifying renderers of script updates.
+  UserScriptLoader loader_;
+
+  ScopedObserver<ExtensionRegistry, ExtensionRegistryObserver>
+      extension_registry_observer_;
+
+  DISALLOW_COPY_AND_ASSIGN(DeclarativeUserScriptMaster);
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_DECLARATIVE_USER_SCRIPT_MASTER_H_