[Telemetry] Add memory and IO stats to page cycler

tools/telemetry/telemetry/core/chrome/android_platform_backend.py

Index: tools/telemetry/telemetry/core/chrome/android_platform_backend.py
diff --git a/tools/telemetry/telemetry/core/chrome/android_platform_backend.py b/tools/telemetry/telemetry/core/chrome/android_platform_backend.py
index 47b9e5bf537b060c1e95d7b2759cec77d51bb6b3..20ede1463d078ce166f8463e096beff2cfdd28fc 100644
--- a/tools/telemetry/telemetry/core/chrome/android_platform_backend.py
+++ b/tools/telemetry/telemetry/core/chrome/android_platform_backend.py
@@ -6,6 +6,8 @@ import logging
 import os
 import sys
 
+from telemetry.core.chrome import platform_backend
+
 # Get build/android scripts into our path.
 sys.path.append(
     os.path.abspath(
@@ -21,7 +23,7 @@ except Exception:
   surface_stats_collector = None
 
 
-class AndroidPlatformBackend(object):
+class AndroidPlatformBackend(platform_backend.PlatformBackend):
   def __init__(self, adb, window_package, window_activity, no_performance_mode):
     super(AndroidPlatformBackend, self).__init__()
     self._adb = adb
@@ -64,3 +66,35 @@ class AndroidPlatformBackend(object):
 
   def HasBeenThermallyThrottled(self):
     return self._thermal_throttle.HasBeenThrottled()
+
+  def GetSystemCommitCharge(self):
+    for line in self._adb.RunShellCommand('dumpsys meminfo', log_result=False):
+      if line.startswith('Total PSS: '):
+        return int(line.split()[2]) * 1024
+    return 0
+
+  def GetMemoryStats(self, pid):
+    memory_usage = self._adb.GetMemoryUsageForPid(pid)[0]
+    return {'ProportionalSetSize': memory_usage['Pss'] * 1024,
+            'PrivateDirty': memory_usage['Private_Dirty'] * 1024}
+
+  def GetIOStats(self, pid):
+    return {}
+
+  def GetChildPids(self, pid):
+    child_pids = []
+    ps = self._adb.RunShellCommand('ps', log_result=False)[1:]
+    for line in ps:
+      data = line.split()
+      curr_pid = data[1]
+      curr_name = data[-1]
+      if int(curr_pid) == pid:
+        name = curr_name
+        for line in ps:
+          data = line.split()
+          curr_pid = data[1]
+          curr_name = data[-1]
+          if curr_name.startswith(name) and curr_name != name:
+            child_pids.append(int(curr_pid))
+        break
+    return child_pids