Autofill: Improve inferring labels from div/td tags.

Do not always infer from tables before divs. If the closest ancestor of
an element is a div, then try to infer from divs first.

Review URL: https://codereview.chromium.org/847433002

Cr-Commit-Position: refs/heads/master@{#310945}

chrome/test/data/autofill/heuristics/output/02_checkout_cafepress.com.out

@@ -20,10 +20,10 @@ ADDRESS_HOME_CITY | ShipCity | Town/City* |  | ShipName_1-default
 ADDRESS_HOME_STATE | ShipState | State/Province* |  | ShipName_1-default
 UNKNOWN_TYPE | ShipStateOther | State/Province* |  | ShipName_1-default
 ADDRESS_HOME_ZIP | ShipZip | Zip/Postal Code* |  | ShipName_1-default
-UNKNOWN_TYPE | ShowGiftMsg | 2 Shipping Address | on | ShipName_1-default
-ADDRESS_HOME_STREET_ADDRESS | GiftMessage | 2 Shipping Address |  | ShipName_1-default
+UNKNOWN_TYPE | ShowGiftMsg | This is a gift order. Check this box to see gift options. | on | ShipName_1-default
+UNKNOWN_TYPE | GiftMessage | One message per order You have |  | ShipName_1-default
 UNKNOWN_TYPE | countdown | You have | 300 | ShipName_1-default
-UNKNOWN_TYPE | ApplyGiftWrap | 2 Shipping Address | on | ShipName_1-default
+UNKNOWN_TYPE | ApplyGiftWrap | (+$0.00) | on | ShipName_1-default
 UNKNOWN_TYPE | txtCoupon | Apply Promo Code |  | ShipName_1-default
 UNKNOWN_TYPE | PaymentMethod |  | PayByCafeCash | ShipName_1-default
 UNKNOWN_TYPE | PaymentMethod |  | PayByGC | ShipName_1-default

chrome/test/data/autofill/heuristics/output/16_crbug_87517.out

@@ -11,8 +11,8 @@ ADDRESS_HOME_COUNTRY | CC_COUNTRY | Country | United States | f1_1-default
 PHONE_HOME_WHOLE_NUMBER | dphone | Telephone |  | f1_1-default
 EMAIL_ADDRESS | demail | Email * |  | f1_1-default
 UNKNOWN_TYPE | amt | $ |  | f1_1-default
-UNKNOWN_TYPE | tributeSelect | Name * | on | f1_1-default
-UNKNOWN_TYPE | DonationType | Name * | OneTime | f1_1-default
+UNKNOWN_TYPE | tributeSelect | Gift amount in USD ($10 minimum) $ | on | f1_1-default
+UNKNOWN_TYPE | DonationType | Gift amount in USD ($10 minimum) $ | OneTime | f1_1-default
 UNKNOWN_TYPE | DonationType | This is a one time donation | Recurs | f1_1-default
 UNKNOWN_TYPE | ccrecurring | I would like to make this a recurring donation deducted | Monthly | f1_1-default
 UNKNOWN_TYPE | remLen | ( You may enter up to 500 characters. ) | 500 | f1_1-default

components/autofill/content/renderer/form_autofill_util.cc

@@ -453,6 +453,25 @@ base::string16 InferLabelFromDefinitionList(
   return FindChildText(previous);
 }
 
+// Returns true if the closest ancestor is a <div> and not a <td>.
+// Returns false if the closest ancestor is a <td> tag,
+// or if there is no <div> or <td> ancestor.
+bool ClosestAncestorIsDivAndNotTD(const WebFormControlElement& element) {
+  for (WebNode parent_node = element.parentNode();
+       !parent_node.isNull();
+       parent_node = parent_node.parentNode()) {
+    if (!parent_node.isElementNode())
+      continue;
+
+    WebElement cur_element = parent_node.to<WebElement>();
+    if (cur_element.hasHTMLTagName("div"))
+      return true;
+    if (cur_element.hasHTMLTagName("td"))
+      return false;
+  }
+  return false;
+}
+
 // Infers corresponding label for |element| from surrounding context in the DOM,
 // e.g. the contents of the preceding <p> tag or text element.
 base::string16 InferLabelForElement(const WebFormControlElement& element) {
@@ -470,6 +489,20 @@ base::string16 InferLabelForElement(const WebFormControlElement& element) {
   if (!inferred_label.empty())
     return inferred_label;
 
+  // If we didn't find a label, check for definition list case.
+  inferred_label = InferLabelFromDefinitionList(element);
+  if (!inferred_label.empty())
+    return inferred_label;
+
+  bool check_div_first = ClosestAncestorIsDivAndNotTD(element);
+  if (check_div_first) {
+    // If we didn't find a label, check for div table case first since it's the
+    // closest ancestor.
+    inferred_label = InferLabelFromDivTable(element);
+    if (!inferred_label.empty())
+      return inferred_label;
+  }
+
   // If we didn't find a label, check for table cell case.
   inferred_label = InferLabelFromTableColumn(element);
   if (!inferred_label.empty())
@@ -480,13 +513,12 @@ base::string16 InferLabelForElement(const WebFormControlElement& element) {
   if (!inferred_label.empty())
     return inferred_label;
 
-  // If we didn't find a label, check for definition list case.
-  inferred_label = InferLabelFromDefinitionList(element);
-  if (!inferred_label.empty())
-    return inferred_label;
-
-  // If we didn't find a label, check for div table case.
-  return InferLabelFromDivTable(element);
+  if (!check_div_first) {
+    // If we didn't find a label from the table, check for div table case if we
+    // haven't already.
+    inferred_label = InferLabelFromDivTable(element);
+  }
+  return inferred_label;
 }
 
 // Fills |option_strings| with the values of the <option> elements present in