[cr tool] Make context implicit

tools/cr/cr/actions/gdb.py

 # Copyright 2013 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.
 
 import os
 
 import cr
 
 
 class GdbDebugger(cr.Debugger):
   """An implementation of cr.Debugger that launches gdb."""
 
   DETECTED = cr.Config('DETECTED')
 
   @property
   def enabled(self):
     return (cr.LinuxPlatform.GetInstance().is_active and
             self.DETECTED.Find('CR_GDB'))
 
-  def Invoke(self, context, targets, arguments):
+  def Invoke(self, targets, arguments):
     for target in targets:
       cr.Host.Execute(
           target,
           '{CR_GDB}', '--eval-command=run', '--args',
           '{CR_BINARY}',
           '{CR_RUN_ARGUMENTS}',
           *arguments
       )
 
-  def Attach(self, context, targets, arguments):
+  def Attach(self, targets, arguments):
     raise NotImplementedError('Attach not currently supported for gdb.')
 
   @classmethod
   def ClassInit(cls):
     # Attempt to find a valid gdb on the path.
     gdb_binaries = cr.Host.SearchPath('gdb')
     if gdb_binaries:
       cls.DETECTED.Set(CR_GDB=gdb_binaries[0])