Fix filesystem API file_handlers to work for drive on ChromeOS.

webkit/fileapi/isolated_context.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 "webkit/fileapi/isolated_context.h"
 
 #include "base/basictypes.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/rand_util.h"
@@ skipping 305 matching lines @@
   std::string mount_name;
   FileSystemType cracked_type;
   base::FilePath cracked_path;
   if (!CrackVirtualPath(path, &mount_name, &cracked_type, &cracked_path))
     return FileSystemURL();
 
   return FileSystemURL(origin, type, path,
                        mount_name, cracked_type, cracked_path);
 }
 
+bool IsolatedContext::GetVirtualPath(const base::FilePath& full_path,
+                                     base::FilePath* virtual_path) const {
+  return false;
+}
+
 void IsolatedContext::RevokeFileSystemByPath(const base::FilePath& path_in) {
   base::AutoLock locker(lock_);
   base::FilePath path(path_in.NormalizePathSeparators());
   PathToID::iterator ids_iter = path_to_id_map_.find(path);
   if (ids_iter == path_to_id_map_.end())
     return;
   std::set<std::string>& ids = ids_iter->second;
   for (std::set<std::string>::iterator iter = ids.begin();
        iter != ids.end(); ++iter) {
     IDToInstance::iterator found = instance_map_.find(*iter);
@@ skipping 79 matching lines @@
   uint32 random_data[4];
   std::string id;
   do {
     base::RandBytes(random_data, sizeof(random_data));
     id = base::HexEncode(random_data, sizeof(random_data));
   } while (instance_map_.find(id) != instance_map_.end());
   return id;
 }
 
 }  // namespace fileapi