Use AtomicString for @keyframes rule names

StyleRuleKeyframes internally stores its name with an AtomicString but
returns it as a String, while there are some other code using StringImpl
for a keyframes name, which causes some confusion.

So this patch unifies all such code to use AtomicString.

Change-Id: Ic7eeff262bcb2ff1c055c9a36ce43ff03ccee1cd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2500954
Auto-Submit: Xiaocheng Hu <xiaochengh@chromium.org>
Reviewed-by: Anders Hartvoll Ruud <andruud@chromium.org>
Commit-Queue: Xiaocheng Hu <xiaochengh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#821325}

third_party/blink/renderer/core/css/css_keyframes_rule.h

@@ -52,7 +52,7 @@ class StyleRuleKeyframes final : public StyleRuleBase {
   void WrapperAppendKeyframe(StyleRuleKeyframe*);
   void WrapperRemoveKeyframe(unsigned);
 
-  String GetName() const { return name_; }
+  AtomicString GetName() const { return name_; }
   void SetName(const String& name) { name_ = AtomicString(name); }
 
   bool IsVendorPrefixed() const { return is_prefixed_; }

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

@@ -143,7 +143,7 @@ void ScopedStyleResolver::ResetAuthorStyle() {
 }
 
 StyleRuleKeyframes* ScopedStyleResolver::KeyframeStylesForAnimation(
-    const StringImpl* animation_name) {
+    const AtomicString& animation_name) {
   if (keyframes_rule_map_.IsEmpty())
     return nullptr;
 
@@ -155,16 +155,16 @@ StyleRuleKeyframes* ScopedStyleResolver::KeyframeStylesForAnimation(
 }
 
 void ScopedStyleResolver::AddKeyframeStyle(StyleRuleKeyframes* rule) {
-  AtomicString s(rule->GetName());
+  AtomicString name = rule->GetName();
 
   if (rule->IsVendorPrefixed()) {
-    KeyframesRuleMap::iterator it = keyframes_rule_map_.find(s.Impl());
+    KeyframesRuleMap::iterator it = keyframes_rule_map_.find(name);
     if (it == keyframes_rule_map_.end())
-      keyframes_rule_map_.Set(s.Impl(), rule);
+      keyframes_rule_map_.Set(name, rule);
     else if (it->value->IsVendorPrefixed())
-      keyframes_rule_map_.Set(s.Impl(), rule);
+      keyframes_rule_map_.Set(name, rule);
   } else {
-    keyframes_rule_map_.Set(s.Impl(), rule);
+    keyframes_rule_map_.Set(name, rule);
   }
 }
 

third_party/blink/renderer/core/css/resolver/scoped_style_resolver.h

@@ -57,7 +57,7 @@ class CORE_EXPORT ScopedStyleResolver final
   ScopedStyleResolver* Parent() const;
 
   StyleRuleKeyframes* KeyframeStylesForAnimation(
-      const StringImpl* animation_name);
+      const AtomicString& animation_name);
 
   void AppendActiveStyleSheets(unsigned index, const ActiveStyleSheetVector&);
   void CollectMatchingAuthorRules(ElementRuleCollector&,
@@ -107,7 +107,7 @@ class CORE_EXPORT ScopedStyleResolver final
   MediaQueryResultList device_dependent_media_query_results_;
 
   using KeyframesRuleMap =
-      HeapHashMap<const StringImpl*, Member<StyleRuleKeyframes>>;
+      HeapHashMap<AtomicString, Member<StyleRuleKeyframes>>;
   KeyframesRuleMap keyframes_rule_map_;
 
   class RuleSubSet final : public GarbageCollected<RuleSubSet> {

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

@@ -1459,7 +1459,7 @@ StyleRuleKeyframes* StyleResolver::FindKeyframesRule(
 
   for (auto& resolver : resolvers) {
     if (StyleRuleKeyframes* keyframes_rule =
-            resolver->KeyframeStylesForAnimation(animation_name.Impl()))
+            resolver->KeyframeStylesForAnimation(animation_name))
       return keyframes_rule;
   }