(Telemetry) Rename Device.device_id to Device.guid

BUG=413637

Review URL: https://codereview.chromium.org/564173002

Cr-Commit-Position: refs/heads/master@{#294651}

tools/telemetry/telemetry/core/platform/__init__.py

@@ -61,20 +61,20 @@ def GetPlatformForDevice(device, logging=real_logging):
     Args:
       device: a device.Device instance.
   """
-  if device.device_id not in _remote_platforms:
+  if device.guid not in _remote_platforms:
     try:
       if isinstance(device, cros_device.CrOSDevice):
         cri = cros_interface.CrOSInterface(
             device.host_name, device.ssh_identity)
         cri.TryLogin()
-        _remote_platforms[device.device_id] = (
+        _remote_platforms[device.guid] = (
             Platform(cros_platform_backend.CrosPlatformBackend(cri)))
       else:
         raise ValueError('Unsupported device type')
     except:
       logging.error('Fail to create platform instance for %s.', device.name)
       raise
-  return _remote_platforms[device.device_id]
+  return _remote_platforms[device.guid]
 
 
 class Platform(object):

tools/telemetry/telemetry/core/platform/cros_device.py

@@ -9,7 +9,8 @@ from telemetry.core.platform import device
 class CrOSDevice(device.Device):
   def __init__(self, host_name, ssh_identity=None):
     super(CrOSDevice, self).__init__(
-        name='ChromeOs with host %s' % host_name, device_id=host_name)
+        name='ChromeOs with host %s' % host_name,
+        guid='cros:%s' % host_name)
     assert host_name
     self._host_name = host_name
     self._ssh_identity = ssh_identity

tools/telemetry/telemetry/core/platform/device.py

@@ -11,22 +11,22 @@ class Device(object):
 
   Attributes:
     name: A device name string in human-understandable term.
-    device_id: A unique id of the device. Subclass of device must specify this
+    guid: A unique id of the device. Subclass of device must specify this
       id properly so that device objects to a same actual device must have same
-      device_id.
+      guid.
     """
 
-  def __init__(self, name, device_id):
+  def __init__(self, name, guid):
     self._name = name
-    self._device_id = device_id
+    self._guid = guid
 
   @property
   def name(self):
     return self._name
 
   @property
-  def device_id(self):
-    return self._device_id
+  def guid(self):
+    return self._guid
 
   @classmethod
   def GetAllConnectedDevices(cls, logging=real_logging):