Mark the single autofilled field when the relevant section is autofilled.

chrome/browser/autofill/autofill_interactive_uitest.cc

 // Copyright (c) 2013 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 <string>
 
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/memory/ref_counted.h"
@@ skipping 465 matching lines @@
   // form.
   SendKeyToPopupAndWait(ui::VKEY_DOWN);
 
   // Press tab to accept the autofill suggestions.
   SendKeyToPopupAndWait(ui::VKEY_TAB);
 
   // The form should be filled.
   ExpectFilledTestForm();
 }
 
+// Test that a field is still autofillable after the previously autofilled
+// value is deleted.
+IN_PROC_BROWSER_TEST_F(AutofillInteractiveTest, OnDeleteValueAfterAutofill) {
+  CreateTestProfile();
+
+  // Load the test page.
+  ASSERT_NO_FATAL_FAILURE(ui_test_utils::NavigateToURL(browser(),
+      GURL(std::string(kDataURIPrefix) + kTestFormString)));
+
+  // Invoke and accept the Autofill popup and verify the form was filled.
+  FocusFirstNameField();
+  SendKeyToPageAndWait(ui::VKEY_M);
+  SendKeyToPopupAndWait(ui::VKEY_DOWN);
+  SendKeyToPopupAndWait(ui::VKEY_RETURN);
+  ExpectFilledTestForm();
+
+  // Delete the value of a filled field.
+  ASSERT_TRUE(content::ExecuteScript(
+      GetRenderViewHost(),
+      "document.getElementById('firstname').value = '';"));
+  ExpectFieldValue("firstname", "");
+
+  // Invoke and accept the Autofill popup and verify the field was filled.
+  SendKeyToPageAndWait(ui::VKEY_M);
+  SendKeyToPopupAndWait(ui::VKEY_DOWN);
+  SendKeyToPopupAndWait(ui::VKEY_RETURN);
+  ExpectFieldValue("firstname", "Milton");
+}
+
 // Test that a JavaScript oninput event is fired after auto-filling a form.
 IN_PROC_BROWSER_TEST_F(AutofillInteractiveTest, OnInputAfterAutofill) {
   CreateTestProfile();
 
   const char kOnInputScript[] =
       "<script>"
       "focused_fired = false;"
       "unfocused_fired = false;"
       "changed_select_fired = false;"
       "unchanged_select_fired = false;"
@@ skipping 735 matching lines @@
   ASSERT_TRUE(content::ExecuteScript(
       GetRenderViewHost(),
       "document.querySelector('input').autocomplete = 'off';"));
 
   // Press the down arrow to select the suggestion and attempt to preview the
   // autofilled form.
   SendKeyToPopupAndWait(ui::VKEY_DOWN);
 }
 
 }  // namespace autofill