Fix python3 failures caused by change 145590579.

Change: 146063650

tensorflow/contrib/session_bundle/exporter_test.py

@@ -183,7 +183,7 @@ class SaveRestoreShardedTest(test.TestCase):
                                  global_step, constants.ASSETS_DIRECTORY,
                                  "hello42.txt")
       asset_contents = gfile.GFile(assets_path).read()
-      self.assertEqual(asset_contents, b"your data here")
+      self.assertEqual(asset_contents, "your data here")
       self.assertEquals("hello42.txt", asset.filename)
       self.assertEquals("filename42:0", asset.tensor_binding.tensor_name)
       ignored_asset_path = os.path.join(export_path,

tensorflow/contrib/session_bundle/session_bundle.py

@@ -82,7 +82,7 @@ def load_session_bundle_from_path(export_dir,
     # Reads meta graph file.
     meta_graph_def = meta_graph_pb2.MetaGraphDef()
     meta_graph_def.ParseFromString(
-        file_io.read_file_to_string(meta_graph_filename))
+        file_io.read_file_to_string(meta_graph_filename, binary_mode=True))
 
   variables_filename = ""
   variables_filename_list = []

tensorflow/python/lib/io/file_io.py

@@ -228,20 +228,25 @@ def delete_file(filename):
     pywrap_tensorflow.DeleteFile(compat.as_bytes(filename), status)
 
 
-def read_file_to_string(filename):
+def read_file_to_string(filename, binary_mode=False):
   """Reads the entire contents of a file to a string.
 
   Args:
     filename: string, path to a file
+    binary_mode: whether to open the file in binary mode or not. This changes
+        the type of the object returned.
 
   Returns:
-    contents of the file as a string
+    contents of the file as a string or bytes.
 
   Raises:
     errors.OpError: Raises variety of errors that are subtypes e.g.
     NotFoundError etc.
   """
-  f = FileIO(filename, mode="r")
+  if binary_mode:
+    f = FileIO(filename, mode="rb")
+  else:
+    f = FileIO(filename, mode="r")
   return f.read()