Add cpu_stats for the browser

tools/telemetry/telemetry/core/platform/proc_util.py

Index: tools/telemetry/telemetry/core/platform/proc_util.py
diff --git a/tools/telemetry/telemetry/core/platform/proc_util.py b/tools/telemetry/telemetry/core/platform/proc_util.py
index 656eb846996b227b9d864798f4793191f2134b15..1449f6aaf2eee97530f3cdde3352e1617c8badb7 100644
--- a/tools/telemetry/telemetry/core/platform/proc_util.py
+++ b/tools/telemetry/telemetry/core/platform/proc_util.py
@@ -22,6 +22,18 @@ def _GetProcFileDict(contents):
   return retval
 
 
+def _GetProcJiffies(timer_list):
+  """Parse '/proc/timer_list' output and returns the first jiffies attribute.
+
+  Multi-CPU machines will have multiple 'jiffies:' lines, all of which will be
+  essentially the same.  Return the first one."""
+  for line in timer_list.splitlines():
+    if line.startswith('jiffies:'):
+      _, value = line.split(':')
+      return value
+  raise Exception('Unable to find jiffies from /proc/timer_list')
+
+
 def GetSystemCommitCharge(meminfo_contents):
   meminfo = _GetProcFileDict(meminfo_contents)
   return (_ConvertKbToByte(meminfo['MemTotal'])
@@ -30,6 +42,25 @@ def GetSystemCommitCharge(meminfo_contents):
           - _ConvertKbToByte(meminfo['Cached']))
 
 
+def GetCpuStats(stats, add_children=False):
+  utime = float(stats[13])
+  stime = float(stats[14])
+  cutime = float(stats[15])
+  cstime = float(stats[16])
+
+  cpu_process_jiffies = utime + stime
+  if add_children:
+    cpu_process_jiffies += cutime + cstime
+
+  return {'CpuProcessTime': cpu_process_jiffies}
+
+
+def GetTimestampJiffies(timer_list):
+  """Return timestamp of system in jiffies."""
+  total_jiffies = float(_GetProcJiffies(timer_list))
+  return {'TotalTime': total_jiffies}
+
+
 def GetMemoryStats(status_contents, stats):
   status = _GetProcFileDict(status_contents)
   if not status or not stats or 'Z' in status['State']: