mojom: Add associative arrays to the mojom language.

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 module mojo {
 
-// A wrapper type which is just a Key/Value pair. Workaround until we get
-// proper maps in mojom.
-struct MimeTypePair {
-  string mime_type;
-  array<uint8> data;
-};
-
 interface Clipboard {
   enum Type {
     COPY_PASTE = 0,
     SELECTION = 1,
     DRAG = 2
   };
 
   // Mime type constants
   const string MIME_TYPE_TEXT = "text/plain";
   const string MIME_TYPE_HTML = "text/html";
@@ skipping 13 matching lines @@
 
   // Returns the data associated with a Mime type, returning NULL if that data
   // doesn't exist. Note: because of the inherit raciness of clipboard access,
   // this may return NULL even if you just verified that it exists with
   // GetAvailableFormatMimeTypes(). We don't want to provide one API to return
   // the entire clipboard state because the combined size of the clipboard can
   // be megabytes, especially when image data is involved.
   ReadMimeType(Type clipboard_type, string mime_type) => (array<uint8>? data);
 
   // Writes a set of mime types to the clipboard. This will increment the
-  // sequence number. In the case of an empty or NULL list, this will just
+  // sequence number. In the case of an empty map, this will just
   // clear the clipboard.
-  WriteClipboardData(Type clipboard_type, array<MimeTypePair>? data);
+  WriteClipboardData(Type clipboard_type, map<string, array<uint8>>? data);
 };
 
 }  // module mojo