Fix misspellings in tensor flow tools (#9574)

tensorflow/tools/common/public_api.py

@@ -38,7 +38,7 @@ class PublicAPIVisitor(object):
     self._visitor = visitor
 
     # Modules/classes we do not want to descend into if we hit them. Usually,
-    # sytem modules exposed through platforms for compatibility reasons.
+    # system modules exposed through platforms for compatibility reasons.
     # Each entry maps a module path to a name to ignore in traversal.
     self._do_not_descend_map = {
         '': [

tensorflow/tools/docs/doc_generator_visitor.py

@@ -170,7 +170,7 @@ class DocGeneratorVisitor(object):
     master names to a lexicographically sorted list of all aliases for that name
     (incl. the master name).
 
-    All these are computed and set as fields if they haven't aready.
+    All these are computed and set as fields if they haven't already.
     """
     if self._reverse_index is not None:
       return

tensorflow/tools/docs/pretty_docs.py

@@ -230,7 +230,7 @@ def _build_signature(obj_info):
 
 
 def _build_compatibility(compatibility):
-  """Return the compatability section as an md string."""
+  """Return the compatibility section as an md string."""
   parts = []
   sorted_keys = sorted(compatibility.keys())
   for key in sorted_keys: