Reland 132134 with memory fix - Use LocalFileReader in FileSystemURLRequestJob

webkit/blob/local_file_reader.h

Index: webkit/blob/local_file_reader.h
diff --git a/webkit/blob/local_file_reader.h b/webkit/blob/local_file_reader.h
index fd87dd450fedf8940801879ffac9559513a61f3b..f7d3b27338bab6469bb80c27e1f4a33c7fbe533f 100644
--- a/webkit/blob/local_file_reader.h
+++ b/webkit/blob/local_file_reader.h
@@ -34,7 +34,9 @@ class BLOB_EXPORT LocalFileReader {
 
   // Creates a new FileReader for a local file |file_path|.
   // |initial_offset| specifies the offset in the file where the first read
-  // should start.
+  // should start.  If the given offset is out of the file range any
+  // read operation may error out with net::ERR_REQUEST_RANGE_NOT_SATISFIABLE.
+  //
   // |expected_modification_time| specifies the expected last modification
   // If the value is non-null, the reader will check the underlying file's
   // actual modification time to see if the file has been modified, and if