mediaview: Introduce ArcDocumentsProviderRoot.

chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root.cc

+// Copyright 2016 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/arc/fileapi/arc_documents_provider_root.h"
+
+#include "base/logging.h"
+#include "content/public/browser/browser_thread.h"
+
+using content::BrowserThread;
+
+namespace arc {
+
+ArcDocumentsProviderRoot::ArcDocumentsProviderRoot(
+    const std::string& authority,
+    const std::string& root_document_id) {}
+
+ArcDocumentsProviderRoot::~ArcDocumentsProviderRoot() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+}
+
+void ArcDocumentsProviderRoot::GetFileInfo(
+    const base::FilePath& path,
+    const GetFileInfoCallback& callback) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  NOTIMPLEMENTED();  // TODO(crbug.com/671511): Implement this function.
+}
+
+void ArcDocumentsProviderRoot::ReadDirectory(
+    const base::FilePath& path,
+    const ReadDirectoryCallback& callback) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  NOTIMPLEMENTED();  // TODO(crbug.com/671511): Implement this function.
+}
+
+}  // namespace arc