Remove simple_util::GetMTime from simple cache.

net/disk_cache/simple/simple_util.h

Index: net/disk_cache/simple/simple_util.h
diff --git a/net/disk_cache/simple/simple_util.h b/net/disk_cache/simple/simple_util.h
index 3bb80b9540238393aa859a9791e6a4faab7d458f..154ee23c7719f3ee8451af83adb8a48436e3b28b 100644
--- a/net/disk_cache/simple/simple_util.h
+++ b/net/disk_cache/simple/simple_util.h
@@ -63,11 +63,7 @@ NET_EXPORT_PRIVATE int64 GetFileOffsetFromKeyAndDataOffset(
     const std::string& key,
     int data_offset);
 
-// Fills |out_time| with the time the file last modified time.
-// TODO(gavinp): Remove this function.
-NET_EXPORT_PRIVATE bool GetMTime(const base::FilePath& path,
-                                 base::Time* out_mtime);
-}  // namespace simple_backend
+}  // namespace simple_util
 
 }  // namespace disk_cache