Remove this unused dependency, backports.weakref is no longer used.

PiperOrigin-RevId: 382633885
Change-Id: I7b16910f6280eda0f14b44ee37dc8fbb92edc396
diff --git a/tensorflow/opensource_only.files b/tensorflow/opensource_only.files
index d69fb58..8b110c7 100644
--- a/tensorflow/opensource_only.files
+++ b/tensorflow/opensource_only.files
@@ -53,7 +53,6 @@
 tensorflow/third_party/arm_neon_2_x86_sse.BUILD
 tensorflow/third_party/astor.BUILD
 tensorflow/third_party/astunparse.BUILD
-tensorflow/third_party/backports_weakref.BUILD
 tensorflow/third_party/boringssl/BUILD
 tensorflow/third_party/clang_toolchain/BUILD
 tensorflow/third_party/clang_toolchain/cc_configure_clang.bzl
diff --git a/tensorflow/python/util/BUILD b/tensorflow/python/util/BUILD
index 63c002d..562659f 100644
--- a/tensorflow/python/util/BUILD
+++ b/tensorflow/python/util/BUILD
@@ -458,7 +458,6 @@
         "//tensorflow/python:global_test_configuration",
         ":tf_decorator",
         ":tf_export",
-        "@org_python_pypi_backports_weakref",
         "@com_google_protobuf//:protobuf_python",
         "//third_party/py/numpy",
         "@six_archive//:six",
diff --git a/tensorflow/tools/pip_package/BUILD b/tensorflow/tools/pip_package/BUILD
index 897bfec..5e220aa 100644
--- a/tensorflow/tools/pip_package/BUILD
+++ b/tensorflow/tools/pip_package/BUILD
@@ -214,7 +214,6 @@
         "@nasm//:LICENSE",
         "@nsync//:LICENSE",
         "@opt_einsum_archive//:LICENSE",
-        "@org_python_pypi_backports_weakref//:LICENSE",
         "@pasta//:LICENSE",
         "@png//:LICENSE",
         "@six_archive//:LICENSE",
diff --git a/tensorflow/workspace2.bzl b/tensorflow/workspace2.bzl
index d0e2a4c..052607f 100644
--- a/tensorflow/workspace2.bzl
+++ b/tensorflow/workspace2.bzl
@@ -517,17 +517,6 @@
     )
 
     tf_http_archive(
-        name = "org_python_pypi_backports_weakref",
-        build_file = "//third_party:backports_weakref.BUILD",
-        sha256 = "8813bf712a66b3d8b85dc289e1104ed220f1878cf981e2fe756dfaabe9a82892",
-        strip_prefix = "backports.weakref-1.0rc1/src",
-        urls = [
-            "https://storage.googleapis.com/mirror.tensorflow.org/pypi.python.org/packages/bc/cc/3cdb0a02e7e96f6c70bd971bc8a90b8463fda83e264fa9c5c1c98ceabd81/backports.weakref-1.0rc1.tar.gz",
-            "https://pypi.python.org/packages/bc/cc/3cdb0a02e7e96f6c70bd971bc8a90b8463fda83e264fa9c5c1c98ceabd81/backports.weakref-1.0rc1.tar.gz",
-        ],
-    )
-
-    tf_http_archive(
         name = "dill_archive",
         build_file = "//third_party:dill.BUILD",
         system_build_file = "//third_party/systemlibs:dill.BUILD",
diff --git a/third_party/backports_weakref.BUILD b/third_party/backports_weakref.BUILD
deleted file mode 100644
index 808ba60..0000000
--- a/third_party/backports_weakref.BUILD
+++ /dev/null
@@ -1,22 +0,0 @@
-# Description:
-#   Backport of new features in Python's weakref module.
-
-package(default_visibility = ["//visibility:public"])
-
-licenses(["notice"])  # Python 2.0
-
-py_library(
-    name = "org_python_pypi_backports_weakref",
-    srcs = [
-        "backports/__init__.py",
-        "backports/weakref.py",
-    ],
-    srcs_version = "PY3",
-)
-
-genrule(
-    name = "license",
-    srcs = ["@org_python_license"],
-    outs = ["LICENSE"],
-    cmd = "cp $< $@",
-)