Remove some deprecated names.

----Release Notes----
[]
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117554610

Author: robertwb

google/cloud/dataflow/transforms/core.py

@@ -18,7 +18,6 @@
 
 import copy
 import uuid
-import warnings
 
 from google.cloud.dataflow import pvalue
 from google.cloud.dataflow import typehints
@@ -820,12 +819,6 @@ def typed(transform):
               | typed(Map('InjectDefault', lambda _, s: s, view)))
 
 
-def Combine(*args, **kwargs):  # pylint: disable=invalid-name
-  warnings.warn('Combine is deprecated, use CombineGlobally instead',
-                DeprecationWarning)
-  return CombineGlobally(*args, **kwargs)
-
-
 @ptransform_fn
 def CombinePerKey(label, pcoll, fn, *args, **kwargs):  # pylint: disable=invalid-name
   """A per-key Combine transform.

google/cloud/dataflow/typehints/decorators.py

@@ -74,7 +74,6 @@ def foo((a, b)):
 
 import inspect
 import types
-import warnings
 
 from google.cloud.dataflow.typehints import check_constraint
 from google.cloud.dataflow.typehints import CompositeTypeHintError
@@ -340,12 +339,6 @@ def annotate(f):
   return annotate
 
 
-def takes(*args, **kwargs):
-  warnings.warn('takes is deprectaed, use with_input_types instead',
-                warnings.DeprecationWarning)
-  return with_input_types(*args, **kwargs)
-
-
 def with_output_types(*return_type_hint, **kwargs):
   """A decorator that type-checks defined type-hints for return values(s).
 
@@ -409,12 +402,6 @@ def annotate(f):
   return annotate
 
 
-def returns(*args, **kwargs):
-  warnings.warn('returns is deprecated, use with_output_types instead',
-                warnings.DeprecationWarning)
-  return with_output_types(*args, **kwargs)
-
-
 def _check_instance_type(
     type_constraint, instance, var_name=None, verbose=False):
   """A helper function to report type-hint constraint violations.