Track SimpleCache memory usage in net/ MemoryDumpProvider

net/disk_cache/simple/simple_entry_impl.cc

Index: net/disk_cache/simple/simple_entry_impl.cc
diff --git a/net/disk_cache/simple/simple_entry_impl.cc b/net/disk_cache/simple/simple_entry_impl.cc
index 23136ba60e541c91b9d5cfccfe0bffb1651df214..a4e4ffd7ede4f75b23aabe89965306e5c6a8c861 100644
--- a/net/disk_cache/simple/simple_entry_impl.cc
+++ b/net/disk_cache/simple/simple_entry_impl.cc
@@ -20,6 +20,7 @@
 #include "base/task_runner_util.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
+#include "base/trace_event/memory_usage_estimator.h"
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
 #include "net/disk_cache/net_log_parameters.h"
@@ -149,6 +150,13 @@ using base::FilePath;
 using base::Time;
 using base::TaskRunner;
 
+// Static function called by base::trace_event::EstimateMemoryUsage() to
+// estimate the memory of SimpleEntryOperation.
+// This needs to be in disk_cache namespace.
+size_t EstimateMemoryUsage(const SimpleEntryOperation& op) {
+  return 0;
+}
+
 // A helper class to insure that RunNextOperationIfNeeded() is called when
 // exiting the current stack frame.
 class SimpleEntryImpl::ScopedOperationRunner {
@@ -543,6 +551,12 @@ int SimpleEntryImpl::ReadyForSparseIO(const CompletionCallback& callback) {
   return net::OK;
 }
 
+size_t SimpleEntryImpl::EstimateMemoryUsage() const {
+  return base::trace_event::EstimateMemoryUsage(pending_operations_) +
+         base::trace_event::EstimateMemoryUsage(executing_operation_) +
+         (stream_0_data_ ? stream_0_data_->capacity() : 0);

[jkarlin, 2017/02/21 16:23:29]

We're missing synchronous_entry_. That's difficult to capture because it lives
on multiple threads, but it could be large.

Perhaps you could include just the sizeof(synchronous_entry_) and comment that
it would be good to have the rest?

[xunjieli, 2017/02/21 19:44:14]

Done. I used sizeof(SimpleSynchronousEntry) because sizeof(synchronous_entry_)
is the sizeof the pointer.

+}
+
 SimpleEntryImpl::~SimpleEntryImpl() {
   DCHECK(io_thread_checker_.CalledOnValidThread());
   DCHECK_EQ(0U, pending_operations_.size());