Mojo: Unify the disparate source and header files into 3

mojo/public/bindings/generators/cpp_templates/params_serialization

Index: mojo/public/bindings/generators/cpp_templates/params_serialization
diff --git a/mojo/public/bindings/generators/cpp_templates/params_serialization b/mojo/public/bindings/generators/cpp_templates/params_serialization
new file mode 100644
index 0000000000000000000000000000000000000000..bc3a928901fb429b0ce1674761c079cb7aed1658
--- /dev/null
+++ b/mojo/public/bindings/generators/cpp_templates/params_serialization
@@ -0,0 +1,18 @@
+template <>
+class ObjectTraits<sample::Service_Frobinate_Params> {
+ public:
+  static void EncodePointersAndHandles(
+      $CLASS* $NAME,
+      std::vector<Handle>* handles) {
+$ENCODES
+$ENCODE_HANDLES
+  }
+
+  static bool DecodePointersAndHandles(
+      $CLASS* $NAME,
+      const Message& message) {
+$DECODES
+$DECODE_HANDLES
+    return true;
+  }
+};