Step 2 in porting disk cache to using FilePath.

net/disk_cache/mapped_file_win.cc

Index: net/disk_cache/mapped_file_win.cc
diff --git a/net/disk_cache/mapped_file_win.cc b/net/disk_cache/mapped_file_win.cc
index 4299df4ac3d8886cb8b137422d0abaad45bdc9d6..06929614c80f86243edcb5b38a06a3a7897ae033 100644
--- a/net/disk_cache/mapped_file_win.cc
+++ b/net/disk_cache/mapped_file_win.cc
@@ -4,6 +4,7 @@
 
 #include "net/disk_cache/mapped_file.h"
 
+#include "base/file_path.h"
 #include "base/logging.h"
 #include "net/disk_cache/disk_cache.h"
 
@@ -11,7 +12,7 @@ namespace disk_cache {
 
 void* MappedFile::Init(const std::wstring& name, size_t size) {
   DCHECK(!init_);
-  if (init_ || !File::Init(name))
+  if (init_ || !File::Init(FilePath::FromWStringHack(name)))
     return NULL;
 
   buffer_ = NULL;