Pass through blink::Element::GetIdAttribute to WebElement

Rather than manually retrieve the "id" attribute, it is cleaner
and faster to use the existing blink::Element method, which is
optimized [1].

This should have no behavior changes.

[1] https://source.chromium.org/chromium/chromium/src/+/master:third_party/blink/renderer/core/dom/element.h;l=1326;drc=9f3ae654ee080ec3ccb5c3f85a51f5e880f5f18e

Change-Id: Ic7634eaa8e8057315d83317862ae16428ee15078
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2628029Reviewed-by: Dominic Battré <battre@chromium.org>
Reviewed-by: Philip Rogers <pdr@chromium.org>
Commit-Queue: Mason Freed <masonfreed@chromium.org>
Cr-Commit-Position: refs/heads/master@{#843783}

components/autofill/content/renderer/form_autofill_util.cc

@@ -1654,10 +1654,8 @@ bool IsWebElementVisible(const blink::WebElement& element) {
 
 base::string16 GetFormIdentifier(const WebFormElement& form) {
   base::string16 identifier = form.GetName().Utf16();
-  static base::NoDestructor<WebString> kId("id");
   if (identifier.empty())
-    identifier = form.GetAttribute(*kId).Utf16();
-
+    identifier = form.GetIdAttribute().Utf16();
   return identifier;
 }
 
@@ -1707,7 +1705,6 @@ void WebFormControlElementToFormField(
   DCHECK(field);
   DCHECK(!element.IsNull());
   static base::NoDestructor<WebString> kAutocomplete("autocomplete");
-  static base::NoDestructor<WebString> kId("id");
   static base::NoDestructor<WebString> kName("name");
   static base::NoDestructor<WebString> kRole("role");
   static base::NoDestructor<WebString> kPlaceholder("placeholder");
@@ -1716,7 +1713,7 @@ void WebFormControlElementToFormField(
   // Save both id and name attributes, if present. If there is only one of them,
   // it will be saved to |name|. See HTMLFormControlElement::nameForAutofill.
   field->name = element.NameForAutofill().Utf16();
-  field->id_attribute = element.GetAttribute(*kId).Utf16();
+  field->id_attribute = element.GetIdAttribute().Utf16();
   field->name_attribute = element.GetAttribute(*kName).Utf16();
   field->unique_renderer_id =
       FieldRendererId(element.UniqueRendererFormControlId());

third_party/blink/public/web/web_element.h

@@ -68,6 +68,8 @@ class BLINK_EXPORT WebElement : public WebNode {
   bool IsEditable() const;
   // Returns the qualified name, which may contain a prefix and a colon.
   WebString TagName() const;
+  // Returns the id attribute.
+  WebString GetIdAttribute() const;
   // Check if this element has the specified local tag name, and the HTML
   // namespace. Tag name matching is case-insensitive.
   bool HasHTMLTagName(const WebString&) const;

third_party/blink/renderer/core/exported/web_element.cc

@@ -80,6 +80,10 @@ WebString WebElement::TagName() const {
   return ConstUnwrap<Element>()->tagName();
 }
 
+WebString WebElement::GetIdAttribute() const {
+  return ConstUnwrap<Element>()->GetIdAttribute();
+}
+
 bool WebElement::HasHTMLTagName(const WebString& tag_name) const {
   // How to create                     class              nodeName localName
   // createElement('input')            HTMLInputElement   INPUT    input