Merge "follows the advice of -Wsign-compare" am: 1545889256 am: c1c27d597c am: 361384c81d

Original change: https://android-review.googlesource.com/c/platform/system/tools/sysprop/+/1613110

Change-Id: I0be2a7b3a2d43f86fb54cd1b07446ce66fe1cfc2
diff --git a/JavaGen.cpp b/JavaGen.cpp
index c2cdaeb..fa4c106 100644
--- a/JavaGen.cpp
+++ b/JavaGen.cpp
@@ -381,7 +381,7 @@
                    GetJavaEnumTypeName(prop).c_str());
       writer.Indent();
       std::vector<std::string> values = ParseEnumValues(prop.enum_values());
-      for (int i = 0; i < values.size(); ++i) {
+      for (std::size_t i = 0; i < values.size(); ++i) {
         const std::string& name = values[i];
         writer.Write("%s(\"%s\")", ToUpper(name).c_str(), name.c_str());
         if (i + 1 < values.size()) {