Implement GetDeviceTypeName on cros.

telemetry/telemetry/core/cros_interface.py

Index: telemetry/telemetry/core/cros_interface.py
diff --git a/telemetry/telemetry/core/cros_interface.py b/telemetry/telemetry/core/cros_interface.py
index 021f8ac939055a293d1299b527cdc643d0937e52..9a82c8b863d641d6eec211cbc7f1fc081baa53e7 100644
--- a/telemetry/telemetry/core/cros_interface.py
+++ b/telemetry/telemetry/core/cros_interface.py
@@ -506,6 +506,19 @@ class CrOSInterface(object):
   def IsRunningOnVM(self):
     return self.SysVendor() == 'QEMU'
 
+  def LsbReleaseValue(self, key, default):
+    """/etc/lsb-release is a file with key=value pairs."""
+    lines = self.GetFileContents('/etc/lsb-release').split('\n')
+    for l in lines:
+      m = re.match(r'([^=]*)=(.*)', l)
+      if m and m.group(1) == key:
+        return m.group(2)
+    return default
+
+  def GetDeviceTypeName(self):
+    """DEVICETYPE in /etc/lsb-release is CHROMEBOOK, CHROMEBIT, etc."""
+    return self.LsbReleaseValue(key='DEVICETYPE', default='CHROMEBOOK')
+
   def RestartUI(self, clear_enterprise_policy):
     logging.info('(Re)starting the ui (logs the user out)')
     if clear_enterprise_policy: