third_party/protobuf: Update to HEAD (f52e188fe4)

third_party/protobuf/src/google/protobuf/source_context.proto

Index: third_party/protobuf/src/google/protobuf/source_context.proto
diff --git a/third_party/protobuf/src/google/protobuf/source_context.proto b/third_party/protobuf/src/google/protobuf/source_context.proto
index d76252ca841edba2598636ef122f264432edce73..f3b2c966811f399fa95fcbf1b2a66911e10ea63a 100644
--- a/third_party/protobuf/src/google/protobuf/source_context.proto
+++ b/third_party/protobuf/src/google/protobuf/source_context.proto
@@ -36,13 +36,13 @@ option csharp_namespace = "Google.Protobuf.WellKnownTypes";
 option java_package = "com.google.protobuf";
 option java_outer_classname = "SourceContextProto";
 option java_multiple_files = true;
-option java_generate_equals_and_hash = true;
 option objc_class_prefix = "GPB";
+option go_package = "google.golang.org/genproto/protobuf/source_context;source_context";
 
 // `SourceContext` represents information about the source of a
 // protobuf element, like the file in which it is defined.
 message SourceContext {
   // The path-qualified name of the .proto file that contained the associated
-  // protobuf element.  For example: `"google/protobuf/source.proto"`.
+  // protobuf element.  For example: `"google/protobuf/source_context.proto"`.
   string file_name = 1;
 }