drive: Rename 'gdata' namespace to 'drive' in chrome/browser/chromeos/drive

chrome/browser/chromeos/drive/document_entry_conversion.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_DRIVE_DOCUMENT_ENTRY_CONVERSION_H_
 #define CHROME_BROWSER_CHROMEOS_DRIVE_DOCUMENT_ENTRY_CONVERSION_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
 
 class GURL;
 
 namespace gdata {
+class DocumentEntry;
+}
 
-class DocumentEntry;
+namespace drive {
+
 class DriveEntryProto;
 
-// Converts a DocumentEntry into a DriveEntryProto.
+// Converts a gdata::DocumentEntry into a DriveEntryProto.
 DriveEntryProto ConvertDocumentEntryToDriveEntryProto(
-    const DocumentEntry& document_entry);
+    const gdata::DocumentEntry& document_entry);
 
-}  // namespace gdata
+}  // namespace drive
 
 #endif  // CHROME_BROWSER_CHROMEOS_DRIVE_DOCUMENT_ENTRY_CONVERSION_H_