Add new wired memory metric to memory-infra dumps.

components/tracing/common/process_metrics_memory_dump_provider.cc

Index: components/tracing/common/process_metrics_memory_dump_provider.cc
diff --git a/components/tracing/common/process_metrics_memory_dump_provider.cc b/components/tracing/common/process_metrics_memory_dump_provider.cc
index c2961357f60eeaf42549955f4abd6ca9d022e6e5..b54b0ec753b05ac48c955223f9de9c4f5468f34d 100644
--- a/components/tracing/common/process_metrics_memory_dump_provider.cc
+++ b/components/tracing/common/process_metrics_memory_dump_provider.cc
@@ -612,13 +612,15 @@ bool ProcessMetricsMemoryDumpProvider::DumpProcessTotals(
   size_t private_bytes;
   size_t shared_bytes;
   size_t resident_bytes;
+  size_t wired_bytes;
   if (!process_metrics_->GetMemoryBytes(&private_bytes, &shared_bytes,
-                                        &resident_bytes)) {
+                                        &resident_bytes, &wired_bytes)) {
     return false;
   }
   uint64_t rss_bytes = resident_bytes;
   pmd->process_totals()->SetExtraFieldInBytes("private_bytes", private_bytes);
   pmd->process_totals()->SetExtraFieldInBytes("shared_bytes", shared_bytes);
+  pmd->process_totals()->SetExtraFieldInBytes("user_wired_bytes", wired_bytes);

[Primiano Tucci (use gerrit), 2017/03/28 20:32:54]

is the "user_" part important? just worrying about column width on the UI.
Also, not sure about what the real semantic of "wired" is, but maybe
"locked_bytes" might be more user friendly? really up to you, I'm fine in any
case

[erikchen, 2017/03/30 00:03:14]

Done.

 #else
   uint64_t rss_bytes = process_metrics_->GetWorkingSetSize();
 #endif  // defined(OS_MACOSX)