Add process start time and CPU time columns to task manager

chrome/browser/task_manager/sampling/task_manager_impl.cc

Index: chrome/browser/task_manager/sampling/task_manager_impl.cc
diff --git a/chrome/browser/task_manager/sampling/task_manager_impl.cc b/chrome/browser/task_manager/sampling/task_manager_impl.cc
index 8d12ca5a5bd60b042b9e5627c9f17cc5e8c4200a..46a8ed017ec0455263f578478e8732b45bc94f52 100644
--- a/chrome/browser/task_manager/sampling/task_manager_impl.cc
+++ b/chrome/browser/task_manager/sampling/task_manager_impl.cc
@@ -10,6 +10,7 @@
 #include <unordered_set>
 #include <vector>
 
+#include "base/bit_cast.h"
 #include "base/command_line.h"
 #include "base/containers/adapters.h"
 #include "build/build_config.h"
@@ -93,6 +94,29 @@ double TaskManagerImpl::GetCpuUsage(TaskId task_id) const {
   return GetTaskGroupByTaskId(task_id)->cpu_usage();
 }
 
+base::Time TaskManagerImpl::GetStartTime(TaskId task_id) const {
+#if defined(OS_WIN)
+  uint64_t time_in_100ns = GetTaskGroupByTaskId(task_id)->start_time();
+  if (time_in_100ns == 0)
+    return base::Time();
+  FILETIME ft = bit_cast<FILETIME, int64_t>(time_in_100ns);
+  return base::Time::FromFileTime(ft);

[afakhry, 2016/12/22 00:28:14]

I'm wondering why we don't do this calculation in the shared_sampler and make it
return the ready-made base::Time and base::TimeDelta values for both the start
and CPU times respectively to the TaskGroup.

Let's keep internal things internal. How about that?

[chengx, 2016/12/22 21:42:55]

Thanks for the suggestion! I have moved the ticks-Time and ticks-TimeDelta
conversions into shared_sampler_win.cc.

+#else
+  return base::Time();
+#endif
+}
+
+base::TimeDelta TaskManagerImpl::GetCpuTime(TaskId task_id) const {
+#if defined(OS_WIN)
+  uint64_t time_in_100ns = GetTaskGroupByTaskId(task_id)->cpu_time();
+  if (time_in_100ns == 0)
+    return base::TimeDelta();
+  return base::TimeDelta::FromMicroseconds(time_in_100ns / 10);
+#else
+  return base::TimeDelta();
+#endif
+}
+
 int64_t TaskManagerImpl::GetPhysicalMemoryUsage(TaskId task_id) const {
   return GetTaskGroupByTaskId(task_id)->physical_bytes();
 }