Track SimpleCache memory usage in net/ MemoryDumpProvider

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 a654faf37182e5287f715c87cce96efc9bc37045..0991b9566fdae4c5ae3c06b9efe7527f51a7438e 100644
--- a/net/disk_cache/simple/simple_index.cc
+++ b/net/disk_cache/simple/simple_index.cc
@@ -23,6 +23,7 @@
 #include "base/task_runner.h"
 #include "base/threading/worker_pool.h"
 #include "base/time/time.h"
+#include "base/trace_event/memory_usage_estimator.h"
 #include "net/base/net_errors.h"
 #include "net/disk_cache/simple/simple_entry_format.h"
 #include "net/disk_cache/simple/simple_histogram_macros.h"
@@ -139,6 +140,10 @@ bool EntryMetadata::Deserialize(base::PickleIterator* it) {
   return true;
 }
 
+size_t EntryMetadata::EstimateMemoryUsage() const {
+  return 0;
+}
+
 SimpleIndex::SimpleIndex(
     const scoped_refptr<base::SingleThreadTaskRunner>& io_thread,
     SimpleIndexDelegate* delegate,
@@ -268,6 +273,10 @@ uint64_t SimpleIndex::GetCacheSizeBetween(base::Time initial_time,
   return size;
 }
 
+size_t SimpleIndex::EstimateMemoryUsage() const {
+  return base::trace_event::EstimateMemoryUsage(entries_set_);

[ssid, 2017/01/31 22:24:19]

Do we need a todo here for other objects here, like removed_entries_ and
index_file_?
Or is it not required if the memory usage is not significant?

[xunjieli, 2017/02/01 01:15:52]

I added |removed_entries_|. SimpleIndexFile doesn't hold on to allocations much.
It's a bunch of static functions.  

+}
+
 void SimpleIndex::Insert(uint64_t entry_hash) {
   DCHECK(io_thread_checker_.CalledOnValidThread());
   // Upon insert we don't know yet the size of the entry.