Fix variable naming style in Element::SetElementAttribute

Rename the local variable |explicitly_set_attr_elements_map_| to
|explicitly_set_attr_elements_map| (dropping the trailing '_').

Change-Id: I2d46f32a993c3c27b092debba48614c068c87060
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2303392
Auto-Submit: Fredrik Söderquist <fs@opera.com>
Commit-Queue: Anders Hartvoll Ruud <andruud@chromium.org>
Reviewed-by: Anders Hartvoll Ruud <andruud@chromium.org>
Cr-Commit-Position: refs/heads/master@{#789509}

third_party/blink/renderer/core/dom/element.cc

@@ -751,7 +751,7 @@ void Element::SynchronizeContentAttributeAndElementReference(
 }
 
 void Element::SetElementAttribute(const QualifiedName& name, Element* element) {
-  ExplicitlySetAttrElementsMap* explicitly_set_attr_elements_map_ =
+  ExplicitlySetAttrElementsMap* explicitly_set_attr_elements_map =
       GetDocument().GetExplicitlySetAttrElementsMap(this);
 
   // If the reflected element is explicitly null, or is not a member of this
@@ -762,7 +762,7 @@ void Element::SetElementAttribute(const QualifiedName& name, Element* element) {
   // https://whatpr.org/html/3917/common-dom-interfaces.html#reflecting-content-attributes-in-idl-attributes:concept-shadow-including-ancestor
   if (!element ||
       !ElementIsDescendantOfShadowIncludingAncestor(*this, *element)) {
-    explicitly_set_attr_elements_map_->erase(name);
+    explicitly_set_attr_elements_map->erase(name);
     removeAttribute(name);
     return;
   }
@@ -782,7 +782,7 @@ void Element::SetElementAttribute(const QualifiedName& name, Element* element) {
   else
     setAttribute(name, id);
 
-  auto result = explicitly_set_attr_elements_map_->insert(name, nullptr);
+  auto result = explicitly_set_attr_elements_map->insert(name, nullptr);
   if (result.is_new_entry) {
     result.stored_value->value =
         MakeGarbageCollected<HeapVector<Member<Element>>>();