Revert of Introduce HostID and de-couple Extensions from "script injection System" [browser side]

chrome/browser/extensions/extension_user_script_loader.h

Index: chrome/browser/extensions/extension_user_script_loader.h
diff --git a/chrome/browser/extensions/extension_user_script_loader.h b/chrome/browser/extensions/extension_user_script_loader.h
deleted file mode 100644
index f23f57aed065c7e27a9aa413e1c8ca78895c784d..0000000000000000000000000000000000000000
--- a/chrome/browser/extensions/extension_user_script_loader.h
+++ /dev/null
@@ -1,59 +0,0 @@
-// Copyright 2015 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_EXTENSION_USER_SCRIPT_LOADER_H_
-#define CHROME_BROWSER_EXTENSIONS_EXTENSION_USER_SCRIPT_LOADER_H_
-
-#include "base/memory/shared_memory.h"
-#include "chrome/browser/extensions/user_script_loader.h"
-#include "extensions/browser/extension_registry_observer.h"
-#include "extensions/common/extension.h"
-
-namespace content {
-class BrowserContext;
-}
-
-class Profile;
-
-namespace extensions {
-
-class ExtensionRegistry;
-
-// UserScriptLoader for extensions.
-class ExtensionUserScriptLoader : public UserScriptLoader,
-                                  public ExtensionRegistryObserver {
- public:
-  // The listen_for_extension_system_loaded is only set true when initilizing
-  // the Extension System, e.g, when constructs SharedUserScriptMaster in
-  // ExtensionSystemImpl.
-  ExtensionUserScriptLoader(Profile* profile,
-                            const HostID& host_id,
-                            bool listen_for_extension_system_loaded);
-  ~ExtensionUserScriptLoader() override;
-
- private:
-  // UserScriptLoader:
-  void UpdateHostsInfo(const std::set<HostID>& changed_hosts) override;
-  LoadUserScriptsContentFunction GetLoadUserScriptsFunction() override;
-
-  // ExtensionRegistryObserver:
-  void OnExtensionUnloaded(content::BrowserContext* browser_context,
-                           const Extension* extension,
-                           UnloadedExtensionInfo::Reason reason) override;
-
-  // Initiates script load when we have been waiting for the extension system
-  // to be ready.
-  void OnExtensionSystemReady();
-
-  ScopedObserver<ExtensionRegistry, ExtensionRegistryObserver>
-      extension_registry_observer_;
-
-  base::WeakPtrFactory<ExtensionUserScriptLoader> weak_factory_;
-
-  DISALLOW_COPY_AND_ASSIGN(ExtensionUserScriptLoader);
-};
-
-}  // namespace extensions
-
-#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_USER_SCRIPT_LOADER_H_