Clarify and separate the concept of "Drive path" and "Filesystem relative path".

chrome/browser/chromeos/file_manager/file_browser_handlers.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/file_manager/file_browser_handlers.h"
 
 #include "base/bind.h"
 #include "base/file_util.h"
 #include "base/i18n/case_conversion.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 242 matching lines @@
       if (!base::PathExists(local_path) ||
           base::IsLink(local_path) ||
           !base::GetFileInfo(local_path, &file_info)) {
         continue;
       }
     }
 
     // Grant access to this particular file to target extension. This will
     // ensure that the target extension can access only this FS entry and
     // prevent from traversing FS hierarchy upward.
-    backend->GrantFileAccessToExtension(
-        handler_extension->id(), virtual_path);
+    backend->GrantFileAccessToExtension(handler_extension->id(), virtual_path);
 
     // Output values.
     FileDefinition file;
     file.virtual_path = virtual_path;
     file.is_directory = file_info.is_directory;
     file.absolute_path = local_path;
     file_list.push_back(file);
   }
   return file_list;
 }
@@ skipping 113 matching lines @@
   // dispatchEvent() method from event_binding.js.
   base::ListValue* file_entries = new base::ListValue();
   details->Set("entries", file_entries);
   for (FileDefinitionList::const_iterator iter = file_list.begin();
        iter != file_list.end();
        ++iter) {
     base::DictionaryValue* file_def = new base::DictionaryValue();
     file_entries->Append(file_def);
     file_def->SetString("fileSystemName", file_system_name);
     file_def->SetString("fileSystemRoot", file_system_root.spec());
-    base::FilePath root(FILE_PATH_LITERAL("/"));
-    base::FilePath full_path = root.Append(iter->virtual_path);
-    file_def->SetString("fileFullPath", full_path.value());
+    file_def->SetString("fileFullPath",
+                        "/" + iter->virtual_path.AsUTF8Unsafe());
     file_def->SetBoolean("fileIsDirectory", iter->is_directory);
   }
 
   scoped_ptr<extensions::Event> event(new extensions::Event(
       "fileBrowserHandler.onExecute", event_args.Pass()));
   event->restrict_to_browser_context = profile_;
   event_router->DispatchEventToExtension(extension_->id(), event.Pass());
 
   ExecuteDoneOnUIThread(true);
 }
@@ skipping 135 matching lines @@
       common_handlers.erase(gallery_iter);
     else
       common_handlers.erase(watch_iter);
   }
 
   return common_handlers;
 }
 
 }  // namespace file_browser_handlers
 }  // namespace file_manager