[android] Convert linker tests to platform mode.

build/android/pylib/base/test_instance_factory.py

 # 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.
 
 from pylib.gtest import gtest_test_instance
 from pylib.instrumentation import instrumentation_test_instance
 from pylib.junit import junit_test_instance
+from pylib.linker import linker_test_instance
 from pylib.monkey import monkey_test_instance
 from pylib.perf import perf_test_instance
 from pylib.utils import device_dependencies
 
 
 def CreateTestInstance(args, error_func):
 
   if args.command == 'gtest':
     return gtest_test_instance.GtestTestInstance(
         args, device_dependencies.GetDataDependencies, error_func)
   elif args.command == 'instrumentation':
     return instrumentation_test_instance.InstrumentationTestInstance(
         args, device_dependencies.GetDataDependencies, error_func)
   elif args.command == 'junit':
     return junit_test_instance.JunitTestInstance(args, error_func)
+  elif args.command == 'linker':
+    return linker_test_instance.LinkerTestInstance(args)
   elif args.command == 'monkey':
     return monkey_test_instance.MonkeyTestInstance(args, error_func)
   elif args.command == 'perf':
     return perf_test_instance.PerfTestInstance(args, error_func)
 
   error_func('Unable to create %s test instance.' % args.command)