mac: Fix calulation for number of resident pages in a process.

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 e181786552df1571bf873c68db81bb9cefe17f17..8462970575d48a1cbdd2b22f6bdca13efe699c47 100644
--- a/components/tracing/common/process_metrics_memory_dump_provider.cc
+++ b/components/tracing/common/process_metrics_memory_dump_provider.cc
@@ -596,9 +596,21 @@ bool ProcessMetricsMemoryDumpProvider::OnMemoryDump(
 bool ProcessMetricsMemoryDumpProvider::DumpProcessTotals(
     const base::trace_event::MemoryDumpArgs& args,
     base::trace_event::ProcessMemoryDump* pmd) {
+#if defined(OS_MACOSX)
+  size_t private_bytes;
+  size_t shared_bytes;
+  if (!process_metrics_->GetMemoryBytes(&private_bytes, &shared_bytes))
+    return false;
+  const uint64_t rss_bytes = rss_bytes_for_testing
+                                 ? rss_bytes_for_testing
+                                 : private_bytes + shared_bytes;

[Mark Mentovai, 2017/03/13 18:13:33]

Same here.

[erikchen, 2017/03/13 21:00:42]

Done.

+  pmd->process_totals()->SetExtraFieldInBytes("private_bytes", private_bytes);

[Primiano Tucci (use gerrit), 2017/03/13 13:59:34]

does this shows up in the UI as is or we need an update in traceviewer? (in the
latter case contact hjd@)

[erikchen, 2017/03/13 21:00:42]

Yes it does. 

I forgot to include this in the original description, but the original code was
never executed, since there was a typo in the preprocessor conditional. I've
updated the CL description to indicate my fix.

+  pmd->process_totals()->SetExtraFieldInBytes("shared_bytes", shared_bytes);
+#else
   const uint64_t rss_bytes = rss_bytes_for_testing
                                  ? rss_bytes_for_testing
                                  : process_metrics_->GetWorkingSetSize();

[Primiano Tucci (use gerrit), 2017/03/13 13:59:34]

maybe you can factor out the ? rss_bytes_for_testing : rss_bytes_for_testing and
just keep a var assignment in the #ifdef?

[erikchen, 2017/03/13 21:00:42]

Done.

+#endif  // defined(OS_MACOSX)
 
   // rss_bytes will be 0 if the process ended while dumping.
   if (!rss_bytes)
@@ -625,12 +637,6 @@ bool ProcessMetricsMemoryDumpProvider::DumpProcessTotals(
     }
     close(clear_refs_fd);
   }
-#elif defined(MACOSX)
-  size_t private_bytes;
-  bool res = process_metrics_->GetMemoryBytes(&private_bytes,
-                                              nullptr /* shared_bytes */);
-  if (res)
-    pmd->process_totals()->SetExtraFieldInBytes("private_bytes", private_bytes);
 #elif defined(OS_WIN)
   if (args.level_of_detail ==
       base::trace_event::MemoryDumpLevelOfDetail::DETAILED) {