Add Equals() to mojom structs and related types.

mojo/public/cpp/bindings/lib/template_util.h

Index: mojo/public/cpp/bindings/lib/template_util.h
diff --git a/mojo/public/cpp/bindings/lib/template_util.h b/mojo/public/cpp/bindings/lib/template_util.h
index c4aeb4302fe4979ec91324def2a1b0d822383e98..6767acf82e78fbc38bcc94c5dd8fb98499eb286f 100644
--- a/mojo/public/cpp/bindings/lib/template_util.h
+++ b/mojo/public/cpp/bindings/lib/template_util.h
@@ -104,6 +104,15 @@ struct RemovePointer<T*> {
   typedef T type;
 };
 
+template <template <typename...> class Template, typename T>
+struct IsSpecializationOf : FalseType {};
+
+template <template <typename...> class Template, typename... Args>
+struct IsSpecializationOf<Template, Template<Args...>> : TrueType {};
+
+template <class A, class B>
+struct LogicalOr : IntegralConstant<bool, A::value || B::value> {};
+
 }  // namespace internal
 }  // namespace mojo