mojom: Add associative arrays to the mojom language.

mojo/services/public/interfaces/clipboard/clipboard.mojom

Index: mojo/services/public/interfaces/clipboard/clipboard.mojom
diff --git a/mojo/services/public/interfaces/clipboard/clipboard.mojom b/mojo/services/public/interfaces/clipboard/clipboard.mojom
index c1e1be4ee09f79244c36d7437d4d918d3e1958c8..6ac7a9c69eeb6cf563be350c00811475a6cbbc64 100644
--- a/mojo/services/public/interfaces/clipboard/clipboard.mojom
+++ b/mojo/services/public/interfaces/clipboard/clipboard.mojom
@@ -47,6 +47,8 @@ interface Clipboard {
   // sequence number. In the case of an empty or NULL list, this will just
   // clear the clipboard.
   WriteClipboardData(Type clipboard_type, MimeTypePair[]? data);
+
+  FakeTestMethod() => (string[string] mapping);

[yzshen1, 2014/09/27 00:01:58]

I think the constraint is that only primitive types and string are allowed to be
key, right? In the case of string, do you allow null as key? (I guess not.)

[Elliot Glaysher, 2014/10/02 19:54:03]

Correct. We verify that we don't pass "string?" at the grammar level. (And then
rely on Array<String> checking the nullness of the incoming strings during
validation.)

 };
 
 }  // module mojo