Revert "Upgrade //third_party/protobuf to v3.2.0"

This reverts commit 2346f5a01561f695a2b2ba7655359d5020105077.

It breaks bazel build in freebsd[1]. The solution is to patch
https://svnweb.freebsd.org/ports/head/devel/protobuf/files/. I
rolled-back this since the other builds will not automatically start if
Bazel is broken.

[1] http://ci.bazel.io/view/Bazel%20bootstrap%20and%20maintenance/job/Bazel/JAVA_VERSION=1.8,PLATFORM_NAME=freebsd-11/1312/

Change-Id: I7e939a4293d799ab6dd67f93d219d1efdf4cd901

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index 420eb9c..0eb938e 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -38,12 +38,6 @@
     actual = "//third_party:guava",
 )
 
-# third_party/protobuf uses gson.
-bind(
-    name = "gson",
-    actual = "//third_party:gson",
-)
-
 # For tools/cpp/test/...
 load("//tools/cpp/test:docker_repository.bzl", "docker_repository")
 docker_repository()
@@ -64,12 +58,12 @@
 
 new_local_repository(
     name = "com_google_protobuf",
-    path = "./third_party/protobuf/3.2.0/",
-    build_file = "./third_party/protobuf/3.2.0/BUILD",
+    path = "./third_party/protobuf/3.0.0/",
+    build_file = "./third_party/protobuf/3.0.0/BUILD",
 )
 
 new_local_repository(
     name = "com_google_protobuf_java",
-    path = "./third_party/protobuf/3.2.0/",
-    build_file = "./third_party/protobuf/3.2.0/BUILD",
+    path = "./third_party/protobuf/3.0.0/",
+    build_file = "./third_party/protobuf/3.0.0/com_google_protobuf_java.BUILD",
 )