[Autofill] Add typemap for autofill:FormFieldData and autofill::FormData.

components/autofill/content/public/interfaces/autofill_types.mojom

Index: components/autofill/content/public/interfaces/autofill_types.mojom
diff --git a/components/autofill/content/public/interfaces/autofill_types.mojom b/components/autofill/content/public/interfaces/autofill_types.mojom
new file mode 100644
index 0000000000000000000000000000000000000000..222f1b8971226ce6e2e18f62848836f021fc2929
--- /dev/null
+++ b/components/autofill/content/public/interfaces/autofill_types.mojom
@@ -0,0 +1,51 @@
+// Copyright 2016 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 autofill.mojom;
+
+import "url/mojo/url.mojom";
+
+// autofill::FormFieldData::RoleAttribute
+enum RoleAttribute {
+  ROLE_ATTRIBUTE_PRESENTATION,
+  ROLE_ATTRIBUTE_OTHER
+};
+
+// base::i18n::TextDirection
+enum TextDirection {
+  UNKNOWN_DIRECTION = 0,
+  RIGHT_TO_LEFT = 1,
+  LEFT_TO_RIGHT = 2,
+  TEXT_DIRECTION_NUM_DIRECTIONS = 3
+};
+
+struct FormFieldData {
+  string label = "";

[yzshen1, 2016/05/23 16:59:13]

Now that you have mapped this to a custom type, do you still care about setting
the default value to ""?
Because that only affects the constructor of auto-generated struct type, which
you probably won't use.

[leonhsl(Using Gerrit), 2016/05/24 06:38:20]

Yeah it's right. Done. Thanks~

+  string name = "";
+  string value = "";
+  string form_control_type = "";
+  string autocomplete_attribute = "";
+  string placeholder = "";
+
+  uint64 max_length;
+  bool is_autofilled;
+  bool is_checked;
+  bool is_checkable;

[dcheng, 2016/05/23 20:43:44]

Is it possible for is_checked to be true but is_checkable to be false?

[leonhsl(Using Gerrit), 2016/05/24 06:38:20]

Checked around is_checked & is_checkable and I suppose if is_checkable was false
then is_checked should always be false based on current code logic, although
there's no any test code checking this now. But as I have no very deep
understanding on the codes, maybe Vaclav can help to confirm this as autofill
OWNER. Thanks ;-)

[vabr (Chromium), 2016/05/24 07:40:30]

Agreed, if is_checkable is false, then is_checked will be false. I filed
http://crbug.com/614280 to make this explicit in the code. (And we even have an
intern starting next week who could do that as their first CL.)

+  bool is_focusable;
+  bool should_autocomplete;
+  RoleAttribute role;
+  TextDirection text_direction;
+
+  array<string> option_values;
+  array<string> option_contents;
+};
+
+struct FormData {
+  string name = "";
+  url.mojom.Url origin;
+  url.mojom.Url action;
+  bool is_form_tag;
+  bool is_formless_checkout;
+  array<FormFieldData> fields;
+};