mojom: Add associative arrays to the mojom language.

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

Index: mojo/public/cpp/bindings/lib/array_serialization.h
diff --git a/mojo/public/cpp/bindings/lib/array_serialization.h b/mojo/public/cpp/bindings/lib/array_serialization.h
index fd18863f80ceaf8c66023aad0ee4eff121758e63..41532388ac212a531c0a840eb6a544dcf3eb3fa8 100644
--- a/mojo/public/cpp/bindings/lib/array_serialization.h
+++ b/mojo/public/cpp/bindings/lib/array_serialization.h
@@ -11,6 +11,7 @@
 
 #include "mojo/public/c/system/macros.h"
 #include "mojo/public/cpp/bindings/lib/array_internal.h"
+#include "mojo/public/cpp/bindings/lib/map_serialization.h"
 #include "mojo/public/cpp/bindings/lib/string_serialization.h"
 #include "mojo/public/cpp/bindings/lib/template_util.h"
 #include "mojo/public/cpp/bindings/lib/validation_errors.h"
@@ -29,6 +30,16 @@ inline void SerializeArray_(Array<E> input,
                             internal::Buffer* buf,
                             internal::Array_Data<F>** output);
 
+template <typename ValueValidateParams,
+          typename KeyWrapperType,
+          typename ValueWrapperType,
+          typename KeySerializationType,
+          typename ValueSerializationType>
+inline void SerializeMap_(
+    Map<KeyWrapperType, ValueWrapperType> input,
+    internal::Buffer* buf,
+    internal::Map_Data<KeySerializationType, ValueSerializationType>** output);
+
 template <typename E, typename F>
 inline void Deserialize_(internal::Array_Data<F>* data, Array<E>* output);
 
@@ -177,6 +188,15 @@ struct ArraySerializer<S, typename S::Data_*, true> {
       SerializeArray_<Params>(input.Pass(), buf, output);
     }
   };
+
+  template <typename T, typename U, typename Params>
+  struct SerializeCaller<Map<T, U>, Params> {
+    static void Run(Map<T, U> input,
+                    Buffer* buf,
+                    typename Map<T, U>::Data_** output) {
+      SerializeMap_<Params>(input.Pass(), buf, output);
+    }
+  };
 };
 
 template <>