Add a field platform_private_footprint_ to ProcessMemoryTotals.

base/process/process_metrics_mac.cc

Index: base/process/process_metrics_mac.cc
diff --git a/base/process/process_metrics_mac.cc b/base/process/process_metrics_mac.cc
index 5eda0d0c7aa869051bae9ae6c4496dc48722bfce..ad751e37f9a1d473be9d98391272a83e26131175 100644
--- a/base/process/process_metrics_mac.cc
+++ b/base/process/process_metrics_mac.cc
@@ -287,18 +287,21 @@ bool ProcessMetrics::GetCommittedAndWorkingSetKBytes(
   return true;
 }
 
-size_t ProcessMetrics::GetPhysicalFootprint() const {
-  if (mac::IsAtMostOS10_11())
-    return 0;
-
+ProcessMetrics::TaskVMInfo ProcessMetrics::GetTaskVMInfo() const {
+  TaskVMInfo info;
   ChromeTaskVMInfo task_vm_info;
   mach_msg_type_number_t count = ChromeTaskVMInfoCount;
   kern_return_t result =
       task_info(TaskForPid(process_), TASK_VM_INFO,
                 reinterpret_cast<task_info_t>(&task_vm_info), &count);
   if (result != KERN_SUCCESS)
-    return 0;
-  return task_vm_info.phys_footprint;
+    return info;
+
+  info.internal = task_vm_info.internal;
+  info.compressed = task_vm_info.compressed;
+  if (count == ChromeTaskVMInfoCount)
+    info.phys_footprint = task_vm_info.phys_footprint;
+  return info;
 }
 
 #define TIME_VALUE_TO_TIMEVAL(a, r) do {  \