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

chrome/browser/autofill/autofill_interactive_uitest.cc

Index: chrome/browser/autofill/autofill_interactive_uitest.cc
diff --git a/chrome/browser/autofill/autofill_interactive_uitest.cc b/chrome/browser/autofill/autofill_interactive_uitest.cc
index 259e568ea3f061cb2c5c57c5de4d5c65770222a9..31ae763e3de5749384053d6f0a3f4efafa58785a 100644
--- a/chrome/browser/autofill/autofill_interactive_uitest.cc
+++ b/chrome/browser/autofill/autofill_interactive_uitest.cc
@@ -483,6 +483,35 @@ IN_PROC_BROWSER_TEST_F(AutofillInteractiveTest, AutofillSelectViaTab) {
   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();