Add SimpleCache index file heuristics

net/disk_cache/simple/simple_index.cc

Index: net/disk_cache/simple/simple_index.cc
diff --git a/net/disk_cache/simple/simple_index.cc b/net/disk_cache/simple/simple_index.cc
index c2b73b9c80716577363e59f05a4387de37bc4181..db075bd4f9c54343dc79213baef760c6a43da62d 100644
--- a/net/disk_cache/simple/simple_index.cc
+++ b/net/disk_cache/simple/simple_index.cc
@@ -173,6 +173,8 @@ void SimpleIndex::InsertInEntrySet(
 }
 
 void SimpleIndex::PostponeWritingToDisk() {
+  if (!initialized_)
+    return;
   const base::TimeDelta file_age = base::Time::Now() - last_write_to_disk_;
   if (file_age > base::TimeDelta::FromSeconds(kMaxWriteToDiskDelaySecs) &&
       write_to_disk_timer_.IsRunning()) {
@@ -194,11 +196,12 @@ void SimpleIndex::LoadFromDisk(
     const base::FilePath& index_filename,
     base::SingleThreadTaskRunner* io_thread,
     const IndexCompletionCallback& completion_callback) {
+  // TODO(felipeg): probably could load a stale index and use it for something.
   scoped_ptr<EntrySet> index_file_entries =
       SimpleIndexFile::LoadFromDisk(index_filename);
 
   bool force_index_flush = false;

[gavinp, 2013/04/19 12:23:13]

This whole function is a lot easier to read. Thanks.

[felipeg, 2013/04/19 12:55:58]

Done.

-  if (!index_file_entries.get()) {
+  if (!index_file_entries) {
     index_file_entries = SimpleIndex::RestoreFromDisk(index_filename);
     // When we restore from disk we write the merged index file to disk right
     // away, this might save us from having to restore again next time.