Add cpu count to trace metadata

base/debug/trace_event_impl.cc

Index: base/debug/trace_event_impl.cc
diff --git a/base/debug/trace_event_impl.cc b/base/debug/trace_event_impl.cc
index a01a10358fa5ca60af72174eb1f11215f4894a51..8bcbe0e45ef55f79ea0c0c81596fdca402afd15f 100644
--- a/base/debug/trace_event_impl.cc
+++ b/base/debug/trace_event_impl.cc
@@ -2049,6 +2049,14 @@ void TraceLog::CancelWatchEvent() {
 void TraceLog::AddMetadataEventsWhileLocked() {
   lock_.AssertAcquired();
 
+#if !defined(OS_NACL)  // NaCl shouldn't expose the process id.

[Ruud van Asseldonk, 2015/12/02 17:00:54]

Either the comment is wrong, or the #if should not be there. This currently
lives in trace_event/trace_log.cc [1] but this appears to be the origin. What
was the intention here?

[1]:
https://chromium.googlesource.com/chromium/src/+/master/base/trace_event/trac...

+  InitializeMetadataEvent(AddEventToThreadSharedChunkWhileLocked(NULL, false),
+                          0,
+                          "num_cpus", "number",
+                          base::SysInfo::NumberOfProcessors());
+#endif
+
+
   int current_thread_id = static_cast<int>(base::PlatformThread::CurrentId());
   if (process_sort_index_ != 0) {
     InitializeMetadataEvent(AddEventToThreadSharedChunkWhileLocked(NULL, false),