Implement in-memory byte hints in SimpleCache

net/disk_cache/simple/simple_synchronous_entry.cc

Index: net/disk_cache/simple/simple_synchronous_entry.cc
diff --git a/net/disk_cache/simple/simple_synchronous_entry.cc b/net/disk_cache/simple/simple_synchronous_entry.cc
index 156e49995807210493f6842b0d73c2a9e357365c..d7e3dde2b41d8f830ba656fef997c809d32b29fb 100644
--- a/net/disk_cache/simple/simple_synchronous_entry.cc
+++ b/net/disk_cache/simple/simple_synchronous_entry.cc
@@ -1449,7 +1449,8 @@ bool SimpleSynchronousEntry::ScanSparseFile(int32_t* out_sparse_data_size) {
     return false;
   }
 
-  if (header.version != kSimpleVersion) {
+  if (header.version < kLastCompatSparseVersion ||
+      header.version > kSimpleVersion) {
     DLOG(WARNING) << "Sparse file unreadable version.";
     return false;
   }