Reverts third_party/protobuf: Update to HEAD (f52e188fe4)

third_party/protobuf/objectivec/Tests/unittest_objc.proto

Index: third_party/protobuf/objectivec/Tests/unittest_objc.proto
diff --git a/third_party/protobuf/objectivec/Tests/unittest_objc.proto b/third_party/protobuf/objectivec/Tests/unittest_objc.proto
index e5577faf0defead95008d9809221a8a3cb87d657..f6ab6a24cab59d953e19561ac6150471536fe88a 100644
--- a/third_party/protobuf/objectivec/Tests/unittest_objc.proto
+++ b/third_party/protobuf/objectivec/Tests/unittest_objc.proto
@@ -29,20 +29,10 @@
 
 syntax = "proto2";
 
-import "google/protobuf/any.proto";
 import "google/protobuf/unittest.proto";
 
 package protobuf_unittest;
 
-// Used to check that Headerdocs and appledoc work correctly. If these comments
-// are not handled correctly, Xcode will fail to build the tests.
-message TestGeneratedComments {
-  // This is a string that could contain stuff like
-  // mime types as image/* or */plain. Maybe twitter usernames
-  // like @protobuf, @google or @something.
-  optional string string_field = 1;
-}
-
 // Using the messages in unittest.proto, setup for recursive cases for testing
 // extensions at various depths.
 extend TestAllExtensions {
@@ -457,11 +447,3 @@ message BoolOnlyMessage {
   optional bool bool_field_31 = 31;
   optional bool bool_field_32 = 32;
 }
-
-// Reference to a WKT to test (via generated code inspection), the handling
-// of #imports.  Within the WKTs, references to each other are just path
-// based imports, but when reference from another proto file, they should be
-// conditional to support the framework import style.
-message WKTRefereceMessage {
-  optional google.protobuf.Any an_any = 1;
-}