Adding a TouchFile() operation.

chrome/browser/file_system/file_system_dispatcher_host.cc

Index: chrome/browser/file_system/file_system_dispatcher_host.cc
===================================================================
--- chrome/browser/file_system/file_system_dispatcher_host.cc	(revision 60236)
+++ chrome/browser/file_system/file_system_dispatcher_host.cc	(working copy)
@@ -115,6 +115,7 @@
     IPC_MESSAGE_HANDLER(ViewHostMsg_FileSystem_Create, OnCreate)
     IPC_MESSAGE_HANDLER(ViewHostMsg_FileSystem_Exists, OnExists)
     IPC_MESSAGE_HANDLER(ViewHostMsg_FileSystem_ReadDirectory, OnReadDirectory)
+    IPC_MESSAGE_HANDLER(ViewHostMsg_FileSystem_TouchFile, OnTouchFile)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP_EX()
   return handled;
@@ -206,6 +207,17 @@
   GetNewOperation(request_id)->ReadDirectory(path);
 }
 
+void FileSystemDispatcherHost::OnTouchFile(
+    int request_id,
+    const FilePath& path,
+    const base::Time& last_access_time,
+    const base::Time& last_modified_time) {
+  if (!CheckValidFileSystemPath(path, request_id))
+    return;
+  GetNewOperation(request_id)->TouchFile(
+      path, last_access_time, last_modified_time);
+}
+
 void FileSystemDispatcherHost::Send(IPC::Message* message) {
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::IO));
   if (!shutdown_ && message_sender_)