Add memory stats for linux page cycler. On linux, we collect

base/process_util_mac.mm

 // Copyright (c) 2008 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/process_util.h"
 
 #import <Cocoa/Cocoa.h>
 #include <crt_externs.h>
 #include <spawn.h>
@@ skipping 215 matching lines @@
     return true;
   return filter_->Includes(entry_.pid, entry_.ppid);
 }
 
 bool ProcessMetrics::GetIOCounters(IoCounters* io_counters) const {
   // TODO(pinkerton): can we implement this? On linux it relies on /proc.
   NOTIMPLEMENTED();
   return false;
 }
 
+size_t ProcessMetrics::GetPagefileUsage() const {
+  NOTIMPLEMENTED();
+  return 0;
+}
+
+size_t ProcessMetrics::GetPeakPagefileUsage() const {
+  NOTIMPLEMENTED();
+  return 0;
+}
+
+size_t ProcessMetrics::GetWorkingSetSize() const {
+  NOTIMPLEMENTED();
+  return 0;
+}
+
+size_t ProcessMetrics::GetPeakWorkingSetSize() const {
+  NOTIMPLEMENTED();
+  return 0;
+}
+
 }  // namespace base