Support creating temporary files for sync file operations.

base/file_util_proxy.h

Index: base/file_util_proxy.h
diff --git a/base/file_util_proxy.h b/base/file_util_proxy.h
index e0b04cb220abd5259c031bef189b5d88ce49930f..e5b0284e6d7745c27ea498828c2a5288b24b0bcb 100644
--- a/base/file_util_proxy.h
+++ b/base/file_util_proxy.h
@@ -64,9 +64,13 @@ class BASE_API FileUtilProxy {
                            CreateOrOpenCallback* callback);
 
   // Creates a temporary file for writing.  The path and an open file handle
-  // are returned.  It is invalid to pass NULL for the callback.
+  // are returned.  It is invalid to pass NULL for the callback.  If async
+  // is true the file temporary file will be opened to support asynchronuous
+  // file operations.  Set async to false if you want to use
+  // FileUtilProxy::Write() on the temporary file.
   static bool CreateTemporary(
       scoped_refptr<MessageLoopProxy> message_loop_proxy,
+      bool aync,

[Sam Kerner (Chrome), 2011/06/03 14:31:42]

Are there reasonable use cases for other sets of file flags?  If so, it might be
better to allow a user to pass in the flags they want.

       CreateTemporaryCallback* callback);
 
   // Close the given file handle.