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

chrome/browser/chromeos/drive/drive_resource_metadata_storage.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_RESOURCE_METADATA_STORAGE_H_
 #define CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_RESOURCE_METADATA_STORAGE_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 103 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(DriveResourceMetadataStorageMemory);
 };
 
 // Implementation of DriveResourceMetadataStorage with leveldb.
 class DriveResourceMetadataStorageDB
     : public DriveResourceMetadataStorage {
  public:
   // This should be incremented when incompatibility change is made to DB
   // format.
-  static const int kDBVersion = 1;
+  static const int kDBVersion = 2;
 
   explicit DriveResourceMetadataStorageDB(const base::FilePath& directory_path);
   virtual ~DriveResourceMetadataStorageDB();
 
   // DriveResourceMetadataStorage overrides:
   virtual bool Initialize() OVERRIDE;
   virtual bool IsPersistentStorage() OVERRIDE;
   virtual void SetLargestChangestamp(int64 largest_changestamp) OVERRIDE;
   virtual int64 GetLargestChangestamp() OVERRIDE;
   virtual void PutEntry(const DriveEntryProto& entry) OVERRIDE;
@@ skipping 27 matching lines @@
 
   // Parent-child relationship between entries.
   scoped_ptr<leveldb::DB> child_map_;
 
   DISALLOW_COPY_AND_ASSIGN(DriveResourceMetadataStorageDB);
 };
 
 }  // namespace drive
 
 #endif  // CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_RESOURCE_METADATA_STORAGE_H_