Use TimeTicks instead of gettimeofday in ProcessMetrics.

base/process/process_metrics_freebsd.cc

Index: base/process/process_metrics_freebsd.cc
diff --git a/base/process/process_metrics_freebsd.cc b/base/process/process_metrics_freebsd.cc
index b0c20d2e916df74f4d791b84a032cf9362d3dd1c..9d4149de2ad8d5af40ee04df68d4fbfc2cb65194 100644
--- a/base/process/process_metrics_freebsd.cc
+++ b/base/process/process_metrics_freebsd.cc
@@ -14,7 +14,6 @@ namespace base {
 
 ProcessMetrics::ProcessMetrics(ProcessHandle process)
     : process_(process),
-      last_cpu_time_(0),
       last_system_time_(0),
       last_cpu_(0) {
   processor_count_ = base::SysInfo::NumberOfProcessors();
@@ -87,11 +86,6 @@ double ProcessMetrics::GetCPUUsage() {
   int mib[] = { CTL_KERN, KERN_PROC, KERN_PROC_PID, process_ };
   size_t length = sizeof(info);
 
-  struct timeval now;
-  int retval = gettimeofday(&now, NULL);
-  if (retval)
-    return 0;
-
   if (sysctl(mib, arraysize(mib), &info, &length, NULL, 0) < 0)
     return 0;