drive: Use "/drive/root" namespace and fix Files app and tests.

chrome/browser/chromeos/drive/drive_file_system.cc

 // Copyright (c) 2012 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/drive/drive_file_system.h"
 
 #include "base/bind.h"
 #include "base/file_util.h"
 #include "base/json/json_file_value_serializer.h"
 #include "base/message_loop_proxy.h"
@@ skipping 1362 matching lines @@
 void DriveFileSystem::SetHideHostedDocuments(bool hide) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   if (hide == hide_hosted_docs_)
     return;
 
   hide_hosted_docs_ = hide;
 
   // Kick off directory refresh when this setting changes.
   FOR_EACH_OBSERVER(DriveFileSystemObserver, observers_,
-                    OnDirectoryChanged(util::GetDriveMyDriveRootPath()));
+                    OnDirectoryChanged(util::GetDriveGrandRootPath()));
 }
 
 //============= DriveFileSystem: internal helper functions =====================
 
 void DriveFileSystem::InitializePreferenceObserver() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   pref_registrar_.reset(new PrefChangeRegistrar());
   pref_registrar_->Init(profile_->GetPrefs());
   pref_registrar_->Add(
@@ skipping 293 matching lines @@
     return;
   }
 
   PlatformFileInfoProto entry_file_info;
   util::ConvertPlatformFileInfoToProto(*file_info, &entry_file_info);
   *entry_proto->mutable_file_info() = entry_file_info;
   callback.Run(DRIVE_FILE_OK, entry_proto.Pass());
 }
 
 }  // namespace drive