Add cpu count to trace metadata

base/debug/trace_event_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/debug/trace_event_impl.h"
 
 #include <algorithm>
 
 #include "base/base_switches.h"
 #include "base/bind.h"
@@ skipping 2031 matching lines @@
 void TraceLog::CancelWatchEvent() {
   AutoLock lock(lock_);
   subtle::NoBarrier_Store(&watch_category_, 0);
   watch_event_name_ = "";
   watch_event_callback_.Reset();
 }
 
 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),
                             current_thread_id,
                             "process_sort_index", "sort_index",
                             process_sort_index_);
   }
 
   if (process_name_.size()) {
     InitializeMetadataEvent(AddEventToThreadSharedChunkWhileLocked(NULL, false),
@@ skipping 358 matching lines @@
 }
 
 ScopedTraceBinaryEfficient::~ScopedTraceBinaryEfficient() {
   if (*category_group_enabled_) {
     TRACE_EVENT_API_UPDATE_TRACE_EVENT_DURATION(category_group_enabled_,
                                                 name_, event_handle_);
   }
 }
 
 }  // namespace trace_event_internal