Fix autocomplete for Gmail subject lines.

chrome/renderer/autofill_helper.cc

 // Copyright (c) 2010 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.
 
 #include "chrome/renderer/autofill_helper.h"
 
 #include "app/l10n_util.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/render_messages.h"
@@ skipping 309 matching lines @@
 
 void AutoFillHelper::QueryAutoFillSuggestions(
     const WebNode& node, bool display_warning_if_disabled) {
   static int query_counter = 0;
   autofill_query_id_ = query_counter++;
   autofill_query_node_ = node;
   display_warning_if_disabled_ = display_warning_if_disabled;
 
   webkit_glue::FormData form;
   webkit_glue::FormField field;
-  if (!FindFormAndFieldForNode(node, &form, &field))
-    return;
+  if (!FindFormAndFieldForNode(node, &form, &field)) {
+    // If we didn't find the cached form, at least let autocomplete have a shot
+    // at providing suggestions.
+    FormManager::WebFormControlElementToFormField(
+        node.toConst<WebFormControlElement>(), FormManager::EXTRACT_VALUE,
+        &field);
+  }
 
   Send(new ViewHostMsg_QueryFormFieldAutoFill(
       routing_id(), autofill_query_id_, form, field));
 }
 
 void AutoFillHelper::FillAutoFillFormData(const WebNode& node,
                                            int unique_id,
                                            AutoFillAction action) {
   static int query_counter = 0;
   autofill_query_id_ = query_counter++;
@@ skipping 45 matching lines @@
                                                 field);
 
   // WebFormControlElementToFormField does not scrape the DOM for the field
   // label, so find the label here.
   // TODO(jhawkins): Add form and field identities so we can use the cached form
   // data in FormManager.
   field->set_label(FormManager::LabelForElement(element));
 
   return true;
 }