third_party/protobuf: Update to HEAD (83d681ee2c)

third_party/protobuf/src/google/protobuf/compiler/java/java_string_field.cc

Index: third_party/protobuf/src/google/protobuf/compiler/java/java_string_field.cc
diff --git a/third_party/protobuf/src/google/protobuf/compiler/java/java_string_field.cc b/third_party/protobuf/src/google/protobuf/compiler/java/java_string_field.cc
index b67eeb5326c8f255df4c84198eb13277d734e543..ff1865b1784dc3ae6ea553bb1570bc27e9976d71 100644
--- a/third_party/protobuf/src/google/protobuf/compiler/java/java_string_field.cc
+++ b/third_party/protobuf/src/google/protobuf/compiler/java/java_string_field.cc
@@ -79,9 +79,11 @@ void SetPrimitiveVariables(const FieldDescriptor* descriptor,
       "    throw new NullPointerException();\n"
       "  }\n";
   (*variables)["writeString"] =
-      "com.google.protobuf.GeneratedMessage.writeString";
+      "com.google.protobuf.GeneratedMessage" + GeneratedCodeVersionSuffix() +
+      ".writeString";
   (*variables)["computeStringSize"] =
-      "com.google.protobuf.GeneratedMessage.computeStringSize";
+      "com.google.protobuf.GeneratedMessage" + GeneratedCodeVersionSuffix() +
+      ".computeStringSize";
 
   // TODO(birdo): Add @deprecated javadoc when generating javadoc is supported
   // by the proto compiler
@@ -712,7 +714,13 @@ void RepeatedImmutableStringFieldGenerator::
 GenerateInterfaceMembers(io::Printer* printer) const {
   WriteFieldDocComment(printer, descriptor_);
   printer->Print(variables_,
-    "$deprecation$com.google.protobuf.ProtocolStringList\n"
+    // NOTE: the same method in the implementation class actually returns
+    // com.google.protobuf.ProtocolStringList (a subclass of List). It's
+    // changed between protobuf 2.5.0 release and protobuf 2.6.1 release.
+    // To retain binary compatibility with both 2.5.0 and 2.6.1 generated
+    // code, we make this interface method return List so both methods
+    // with different return types exist in the compiled byte code.
+    "$deprecation$java.util.List<java.lang.String>\n"
     "    get$capitalized_name$List();\n");
   WriteFieldDocComment(printer, descriptor_);
   printer->Print(variables_,