Added frequency stats and c-state residency to CrOS power monitor.

tools/telemetry/telemetry/core/platform/power_monitor/sysfs_platform.py

Index: tools/telemetry/telemetry/core/platform/power_monitor/sysfs_platform.py
diff --git a/tools/telemetry/telemetry/core/platform/power_monitor/sysfs_platform.py b/tools/telemetry/telemetry/core/platform/power_monitor/sysfs_platform.py
new file mode 100644
index 0000000000000000000000000000000000000000..b16808b4484f7e92d2c784bc4c0a9f0d790925e7
--- /dev/null
+++ b/tools/telemetry/telemetry/core/platform/power_monitor/sysfs_platform.py
@@ -0,0 +1,34 @@
+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+class SysfsPlatform(object):
+  """A platform-specific utility class for running shell commands and properly
+  gathering c-state data.
+  """
+  def RunShellCommand(self, command):
+    """Run command on this particular shell.
+
+    Args:
+        A command string to be executed in the shell.
+
+    Returns:
+        A string containing the results of the command.
+    """
+    raise NotImplementedError()
+
+  @staticmethod
+  def ParseStateSample(sample, time):
+    """Parse a single c-state residency sample.
+
+    Args:
+        sample: A sample of c-state residency times to be parsed. Organized as
+            a dictionary mapping CPU name to a string containing all c-state
+            names, the times in each state, and the latency of each state all
+            separated by newlines.
+        time: The epoch time at which the sample was taken.
+
+    Returns:
+        Dictionary associating a c-state with a time.
+    """
+    raise NotImplementedError()