Revert 34994, maybe it regressed startup perf - Fix cpu/memory measurements o...

base/process_util_mac.mm

Index: base/process_util_mac.mm
===================================================================
--- base/process_util_mac.mm	(revision 35019)
+++ base/process_util_mac.mm	(working copy)
@@ -182,46 +182,23 @@
 // ------------------------------------------------------------------------
 // NOTE: about ProcessMetrics
 //
-// Getting a mach task from a pid for another process requires permissions in
-// general, so there doesn't really seem to be a way to do these (and spinning
-// up ps to fetch each stats seems dangerous to put in a base api for anyone to
-// call). Child processes ipc their port, so return something if available,
-// otherwise return 0.
+// Mac doesn't have /proc, and getting a mach task from a pid for another
+// process requires permissions, so there doesn't really seem to be a way
+// to do these (and spinning up ps to fetch each stats seems dangerous to
+// put in a base api for anyone to call.
 //
 bool ProcessMetrics::GetIOCounters(IoCounters* io_counters) const {
   return false;
 }
-
-static bool GetTaskInfo(mach_port_t task, task_basic_info_64* task_info_data) {
-  if (!task)
-    return false;
-  mach_msg_type_number_t count = TASK_BASIC_INFO_64_COUNT;
-  kern_return_t kr = task_info(task,
-                               TASK_BASIC_INFO_64,
-                               reinterpret_cast<task_info_t>(task_info_data),
-                               &count);
-  // Most likely cause for failure: |task| is a zombie.
-  return kr == KERN_SUCCESS;
-}
-
 size_t ProcessMetrics::GetPagefileUsage() const {
-  task_basic_info_64 task_info_data;
-  if (!GetTaskInfo(TaskForPid(process_), &task_info_data))
-    return 0;
-  return task_info_data.virtual_size;
+  return 0;
 }
-
 size_t ProcessMetrics::GetPeakPagefileUsage() const {
   return 0;
 }
-
 size_t ProcessMetrics::GetWorkingSetSize() const {
-  task_basic_info_64 task_info_data;
-  if (!GetTaskInfo(TaskForPid(process_), &task_info_data))
-    return 0;
-  return task_info_data.resident_size;
+  return 0;
 }
-
 size_t ProcessMetrics::GetPeakWorkingSetSize() const {
   return 0;
 }
@@ -234,97 +211,9 @@
 }
 
 bool ProcessMetrics::GetWorkingSetKBytes(WorkingSetKBytes* ws_usage) const {
-  size_t priv = GetWorkingSetSize();
-  if (!priv)
-    return false;
-  ws_usage->priv = priv / 1024;
-  ws_usage->shareable = 0;
-  ws_usage->shared = 0;
-  return true;
+  return false;
 }
 
-#define TIME_VALUE_TO_TIMEVAL(a, r) do {  \
-  (r)->tv_sec = (a)->seconds;             \
-  (r)->tv_usec = (a)->microseconds;       \
-} while (0)
-
-int ProcessMetrics::GetCPUUsage() {
-  mach_port_t task = TaskForPid(process_);
-  if (!task)
-    return 0;
-
-  kern_return_t kr;
-
-  // TODO(thakis): Libtop doesn't use thread info. How can they get away
-  // without it?
-  task_thread_times_info thread_info_data;
-  mach_msg_type_number_t thread_info_count = TASK_THREAD_TIMES_INFO_COUNT;
-  kr = task_info(task,
-                 TASK_THREAD_TIMES_INFO,
-                 reinterpret_cast<task_info_t>(&thread_info_data),
-                 &thread_info_count);
-  if (kr != KERN_SUCCESS) {
-    // Most likely cause: |task| is a zombie.
-    return 0;
-  }
-
-  task_basic_info_64 task_info_data;
-  if (!GetTaskInfo(task, &task_info_data))
-    return 0;
-
-  /* Set total_time. */
-  // thread info contains live time...
-  struct timeval user_timeval, system_timeval, task_timeval;
-  TIME_VALUE_TO_TIMEVAL(&thread_info_data.user_time, &user_timeval);
-  TIME_VALUE_TO_TIMEVAL(&thread_info_data.system_time, &system_timeval);
-  timeradd(&user_timeval, &system_timeval, &task_timeval);
-
-  // ... task info contains terminated time.
-  TIME_VALUE_TO_TIMEVAL(&task_info_data.user_time, &user_timeval);
-  TIME_VALUE_TO_TIMEVAL(&task_info_data.system_time, &system_timeval);
-  timeradd(&user_timeval, &task_timeval, &task_timeval);
-  timeradd(&system_timeval, &task_timeval, &task_timeval);
-
-  struct timeval now;
-  int retval = gettimeofday(&now, NULL);
-  if (retval)
-    return 0;
-
-  int64 time = TimeValToMicroseconds(now);
-  int64 task_time = TimeValToMicroseconds(task_timeval);
-
-  if ((last_system_time_ == 0) || (last_time_ == 0)) {
-    // First call, just set the last values.
-    last_system_time_ = task_time;
-    last_time_ = time;
-    return 0;
-  }
-
-  int64 system_time_delta = task_time - last_system_time_;
-  int64 time_delta = time - last_time_;
-  DCHECK(time_delta != 0);
-  if (time_delta == 0)
-    return 0;
-
-  // We add time_delta / 2 so the result is rounded.
-  int cpu = static_cast<int>((system_time_delta * 100 + time_delta / 2) /
-                             (time_delta));
-
-  last_system_time_ = task_time;
-  last_time_ = time;
-
-  return cpu;
-}
-
-mach_port_t ProcessMetrics::TaskForPid(ProcessHandle process) const {
-  mach_port_t task = 0;
-  if (port_provider_)
-    task = port_provider_->TaskForPid(process_);
-  if (!task && process_ == getpid())
-    task = mach_task_self();
-  return task;
-}
-
 // ------------------------------------------------------------------------
 
 // Bytes committed by the system.