Remove the usage of BrowserThread::FILE in the shell_integration* files

chrome/browser/custom_handlers/protocol_handler_registry.h

Index: chrome/browser/custom_handlers/protocol_handler_registry.h
diff --git a/chrome/browser/custom_handlers/protocol_handler_registry.h b/chrome/browser/custom_handlers/protocol_handler_registry.h
index 25f712cad488c86ec27cc4f5ba1c289c5ab6ef0e..ca01a8184829b0ed0f9b3c6f31a17cd26e6a9a23 100644
--- a/chrome/browser/custom_handlers/protocol_handler_registry.h
+++ b/chrome/browser/custom_handlers/protocol_handler_registry.h
@@ -49,10 +49,6 @@ class ProtocolHandlerRegistry : public KeyedService {
     virtual void RegisterExternalHandler(const std::string& protocol);
     virtual void DeregisterExternalHandler(const std::string& protocol);
     virtual bool IsExternalHandlerRegistered(const std::string& protocol);
-    virtual scoped_refptr<shell_integration::DefaultProtocolClientWorker>
-    CreateShellWorker(
-        const shell_integration::DefaultWebClientWorkerCallback& callback,
-        const std::string& protocol);
     virtual void RegisterWithOSAsDefaultClient(
         const std::string& protocol,
         ProtocolHandlerRegistry* registry);