[fsp] Introduce file_system_provider::Service class for the FileSystemProvider API.

chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.cc

 // Copyright 2013 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 "chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.h"
 
+#include "chrome/browser/chromeos/file_system_provider/service.h"
 #include "chrome/common/extensions/api/file_system_provider.h"
 
 namespace extensions {
-
 namespace {
 
 // Error names from
 // http://www.w3.org/TR/file-system-api/#errors-and-exceptions
 const char kSecurityErrorName[] = "SecurityError";
 
 // Error messages.
-const char kEmptyNameErrorMessage[] = "Empty display name is not allowed";
+const char kEmptyNameErrorMessage[] = "Empty display name is not allowed.";
+const char kRegisteringFailedErrorMessage[] =
+    "Registering the file system failed.";
 
 // Creates a dictionary, which looks like a DOMError. The returned dictionary
 // will be converted to a real DOMError object in
 // file_system_provier_custom_bindings.js.
 base::DictionaryValue* CreateError(const std::string& name,
                                    const std::string& message) {
   base::DictionaryValue* error = new base::DictionaryValue();
   error->SetString("name", name);
   error->SetString("message", message);
   return error;
 }
 
 }  // namespace
 
 bool FileSystemProviderMountFunction::RunImpl() {
   using extensions::api::file_system_provider::Mount::Params;
   const scoped_ptr<Params> params(Params::Create(*args_));
   EXTENSION_FUNCTION_VALIDATE(params);
 
   // It's an error if the display name is empty.
   if (params->display_name.empty()) {
-    const std::string file_system_id = "";
-
     base::ListValue* result = new base::ListValue();
-    result->Append(new base::StringValue(file_system_id));
+    result->Append(new base::StringValue(""));
     result->Append(CreateError(kSecurityErrorName,
                                kEmptyNameErrorMessage));
     SetResult(result);
-    SendResponse(true);
-    return true;
+    return false;
   }
 
-  // TODO(satorux): Implement the real logic.
-  const std::string file_system_id = params->display_name;
+  chromeos::file_system_provider::Service* service =
+      chromeos::file_system_provider::Service::Get(GetProfile());
+  DCHECK(service);
+
+  const std::string file_system_id =
+      service->RegisterFileSystem(extension_id(), params->display_name);
+
+  // If the |file_system_id| is empty, then it means that registering the file
+  // system failed.
+  // TODO(mtomasz): Pass more detailed errors, rather than just a bool.
+  if (file_system_id.empty()) {
+    base::ListValue* result = new base::ListValue();
+    result->Append(new base::StringValue(""));
+    result->Append(
+        CreateError(kSecurityErrorName, kRegisteringFailedErrorMessage));
+    SetResult(result);
+    return false;
+  }
 
   base::ListValue* result = new base::ListValue();
   result->Append(new base::StringValue(file_system_id));
   // Don't append an error on success.
 
   SetResult(result);
   SendResponse(true);
   return true;
 }
 
 }  // namespace extensions