Use new downcast helper for blink::HTMLDivElement

This CL has two goals,
  1. Use To<HTMLDivElement> and DynamicTo<HTMLDivElement> as new
   downcast helper
  2. Use IsA<HTMLDivElement>(element) in place of
   IsHTMLDivElement(element)

Bug: 891908
Change-Id: Icf2b04b39e87af309a7fc5d66fbd402ae8ed8b0d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1930765Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Christian Biesinger <cbiesinger@chromium.org>
Commit-Queue: Abhijeet | Igalia <abhijeet@igalia.com>
Cr-Commit-Position: refs/heads/master@{#719062}

third_party/blink/renderer/core/css/resolver/style_adjuster.cc

@@ -201,7 +201,7 @@ static void AdjustStyleForHTMLElement(ComputedStyle& style,
                                       HTMLElement& element) {
   // <div> and <span> are the most common elements on the web, we skip all the
   // work for them.
-  if (IsHTMLDivElement(element) || IsA<HTMLSpanElement>(element))
+  if (IsA<HTMLDivElement>(element) || IsA<HTMLSpanElement>(element))
     return;
 
   if (IsHTMLTableCellElement(element)) {

third_party/blink/renderer/core/editing/commands/composite_edit_command.cc

@@ -265,15 +265,15 @@ void CompositeEditCommand::InsertParagraphSeparator(
 
 bool CompositeEditCommand::IsRemovableBlock(const Node* node) {
   DCHECK(node);
-  if (!IsHTMLDivElement(*node))
+  const auto* element = DynamicTo<HTMLDivElement>(node);
+  if (!element)
     return false;
 
-  const HTMLDivElement& element = ToHTMLDivElement(*node);
-  ContainerNode* parent_node = element.parentNode();
+  ContainerNode* parent_node = element->parentNode();
   if (parent_node && parent_node->firstChild() != parent_node->lastChild())
     return false;
 
-  if (!element.hasAttributes())
+  if (!element->hasAttributes())
     return true;
 
   return false;

third_party/blink/renderer/core/editing/commands/insert_paragraph_separator_command.cc

@@ -56,7 +56,7 @@ static Element* HighestVisuallyEquivalentDivBelowRoot(Element* start_block) {
   // We don't want to return a root node (if it happens to be a div, e.g., in a
   // document fragment) because there are no siblings for us to append to.
   while (!cur_block->nextSibling() &&
-         IsHTMLDivElement(*cur_block->parentElement()) &&
+         IsA<HTMLDivElement>(*cur_block->parentElement()) &&
          cur_block->parentElement()->parentElement()) {
     if (cur_block->parentElement()->hasAttributes())
       break;
@@ -322,7 +322,7 @@ void InsertParagraphSeparatorCommand::DoApply(EditingState* editing_state) {
         // startBlock (e.g., when nesting within lists). However, for div nodes,
         // this can result in nested div tags that are hard to break out of.
         Element* sibling_element = start_block;
-        if (IsHTMLDivElement(*block_to_insert))
+        if (IsA<HTMLDivElement>(*block_to_insert))
           sibling_element = HighestVisuallyEquivalentDivBelowRoot(start_block);
         InsertNodeAfter(block_to_insert, sibling_element, editing_state);
       }

third_party/blink/renderer/core/editing/serializers/serialization.cc

@@ -500,20 +500,21 @@ static void FillContainerFromString(ContainerNode* paragraph,
 
 bool IsPlainTextMarkup(Node* node) {
   DCHECK(node);
-  if (!IsHTMLDivElement(*node))
+  auto* element = DynamicTo<HTMLDivElement>(*node);
+  if (!element)
     return false;
 
-  HTMLDivElement& element = ToHTMLDivElement(*node);
-  if (!element.hasAttributes())
+  if (!element->hasAttributes())
     return false;
 
-  if (element.HasOneChild())
-    return element.firstChild()->IsTextNode() ||
-           element.firstChild()->hasChildren();
+  if (element->HasOneChild()) {
+    return element->firstChild()->IsTextNode() ||
+           element->firstChild()->hasChildren();
+  }
 
-  return element.HasChildCount(2) &&
-         IsTabHTMLSpanElementTextNode(element.firstChild()->firstChild()) &&
-         element.lastChild()->IsTextNode();
+  return element->HasChildCount(2) &&
+         IsTabHTMLSpanElementTextNode(element->firstChild()->firstChild()) &&
+         element->lastChild()->IsTextNode();
 }
 
 static bool ShouldPreserveNewline(const EphemeralRange& range) {

third_party/blink/renderer/core/frame/smart_clip.cc

@@ -195,7 +195,7 @@ Node* SmartClip::FindBestOverlappingNode(Node* root_node,
 bool SmartClip::ShouldSkipBackgroundImage(Node* node) {
   DCHECK(node);
   // Apparently we're only interested in background images on spans and divs.
-  if (!IsA<HTMLSpanElement>(*node) && !IsHTMLDivElement(*node))
+  if (!IsA<HTMLSpanElement>(*node) && !IsA<HTMLDivElement>(*node))
     return true;
 
   // This check actually makes a bit of sense. If you're going to sprite an

third_party/blink/renderer/core/html/media/html_video_element_persistent_test.cc

@@ -50,7 +50,7 @@ class HTMLVideoElementPersistentTest : public PageTestBase {
   }
 
   HTMLDivElement* DivElement() {
-    return ToHTMLDivElement(GetDocument().QuerySelector("div"));
+    return To<HTMLDivElement>(GetDocument().QuerySelector("div"));
   }
 
   Element* FullscreenElement() {

third_party/blink/renderer/modules/accessibility/ax_node_object.cc

@@ -720,7 +720,7 @@ ax::mojom::Role AXNodeObject::NativeRoleIgnoringAria() const {
   if (HeadingLevel())
     return ax::mojom::Role::kHeading;
 
-  if (IsHTMLDivElement(*GetNode()))
+  if (IsA<HTMLDivElement>(*GetNode()))
     return ax::mojom::Role::kGenericContainer;
 
   if (IsA<HTMLMeterElement>(*GetNode()))
@@ -1169,7 +1169,7 @@ bool AXNodeObject::IsInPageLinkTarget() const {
 
   if (element->HasID() &&
       (IsLandmarkRelated() || IsA<HTMLSpanElement>(element) ||
-       IsHTMLDivElement(element))) {
+       IsA<HTMLDivElement>(element))) {
     return true;
   }
   return false;