Add experimental private memory footprint metrics.

chrome/browser/memory_details_mac.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 "chrome/browser/memory_details.h"
 
 #include <stddef.h>
 
 #include <memory>
 #include <set>
 #include <string>
 
 #include "base/bind.h"
 #include "base/file_version_info.h"
 #include "base/files/file_path.h"
 #include "base/mac/foundation_util.h"
+#include "base/mac/mac_util.h"
 #include "base/process/process_iterator.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread.h"
 #include "base/threading/thread_restrictions.h"
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/grit/chromium_strings.h"
 #include "components/version_info/version_info.h"
 #include "content/public/browser/browser_child_process_host.h"
@@ skipping 28 matching lines @@
       info.titles = child.titles;
       info.process_type = child.process_type;
       break;
     }
   }
 
   std::unique_ptr<base::ProcessMetrics> metrics =
       base::ProcessMetrics::CreateProcessMetrics(
           pid, content::BrowserChildProcessHost::GetPortProvider());
   metrics->GetCommittedAndWorkingSetKBytes(&info.committed, &info.working_set);
-  info.phys_footprint = metrics->GetTaskVMInfo().phys_footprint;
+  base::ProcessMetrics::TaskVMInfo vm_info = metrics->GetTaskVMInfo();
+  info.phys_footprint = vm_info.phys_footprint;
+
+  // TODO(erikchen): Remove this temporary estimate for private memory once the
+  // memory infra service emits the same metric. https://crbug.com/720541.
+  if (base::mac::IsAtLeastOS10_12()) {
+    info.private_memory_footprint = vm_info.phys_footprint;

[Nico, 2017/05/11 20:12:59]

are you sure that you want to send differently computed things on different OS?
This means this metric will be useless to look at unless you split by os.

[erikchen, 2017/05/11 21:02:22]

Yup. The first API is strictly better, but not available on older OSes. This is
an experimental, temporary metric and I'll remember to split.

When we do this officially, we probably will want to have separately named UMA
metrics to avoid confusion.

+  } else {
+    info.private_memory_footprint = vm_info.internal + vm_info.compressed;
+  }
 
   processes->push_back(info);
 }
 
 }  // namespace
 
 MemoryDetails::MemoryDetails() {
   const base::FilePath browser_process_path =
       base::GetProcessExecutablePath(base::GetCurrentProcessHandle());
 
@@ skipping 46 matching lines @@
 
   // Collect data about Chrome/Chromium.
   for (const base::ProcessId& pid : all_pids)
     CollectProcessDataForChromeProcess(child_info, pid, chrome_processes);
 
   // Finally return to the browser thread.
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(&MemoryDetails::CollectChildInfoOnUIThread, this));
 }