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

components/tracing/common/process_metrics_memory_dump_provider.cc

 // Copyright 2015 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 "components/tracing/common/process_metrics_memory_dump_provider.h"
 
 #include <fcntl.h>
 #include <stdint.h>
 
 #include <map>
@@ skipping 578 matching lines @@
 
   if (args.level_of_detail ==
       base::trace_event::MemoryDumpLevelOfDetail::DETAILED)
     res &= DumpProcessMemoryMaps(args, pmd);
   return res;
 }
 
 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)
     return false;
 
   uint64_t peak_rss_bytes = 0;
 
 #if !defined(OS_IOS)
   peak_rss_bytes = process_metrics_->GetPeakWorkingSetSize();
 #if defined(OS_LINUX) || defined(OS_ANDROID)
   if (is_rss_peak_resettable_) {
     std::string clear_refs_file =
         "/proc/" +
         (process_ == base::kNullProcessId ? "self"
                                           : base::IntToString(process_)) +
         "/clear_refs";
     int clear_refs_fd = open(clear_refs_file.c_str(), O_WRONLY);
     if (clear_refs_fd > 0 &&
         base::WriteFileDescriptor(clear_refs_fd, kClearPeakRssCommand,
                                   sizeof(kClearPeakRssCommand))) {
       pmd->process_totals()->set_is_peak_rss_resetable(true);
     } else {
       is_rss_peak_resettable_ = false;
     }
     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) {
     uint64_t pss_bytes = 0;
     bool res = process_metrics_->GetProportionalSetSizeBytes(&pss_bytes);
     if (res) {
       base::trace_event::ProcessMemoryMaps::VMRegion region;
       region.byte_stats_proportional_resident = pss_bytes;
       pmd->process_mmaps()->AddVMRegion(region);
       pmd->set_has_process_mmaps();
@@ skipping 41 matching lines @@
 #endif
 }
 
 void ProcessMetricsMemoryDumpProvider::SuspendFastMemoryPolling() {
 #if defined(OS_LINUX) || defined(OS_ANDROID)
   fast_polling_statm_fd_.reset();
 #endif
 }
 
 }  // namespace tracing