Optimize style recalc when adding @keyframes.

third_party/WebKit/Source/core/css/invalidation/StyleSheetInvalidationAnalysis.cpp

 /*
  * Copyright (C) 2012 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 14 matching lines @@
 
 #include "core/css/invalidation/StyleSheetInvalidationAnalysis.h"
 
 #include "core/css/CSSSelectorList.h"
 #include "core/css/StyleRuleImport.h"
 #include "core/css/StyleSheetContents.h"
 #include "core/dom/ContainerNode.h"
 #include "core/dom/Document.h"
 #include "core/dom/ElementTraversal.h"
 #include "core/dom/StyleChangeReason.h"
+#include "core/dom/StyleEngine.h"
 #include "core/dom/TreeScope.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/html/HTMLStyleElement.h"
 
 namespace blink {
 
 StyleSheetInvalidationAnalysis::StyleSheetInvalidationAnalysis(const TreeScope& treeScope, const HeapVector<Member<StyleSheetContents>>& sheets)
     : m_treeScope(&treeScope)
 {
     for (unsigned i = 0; i < sheets.size() && !m_dirtiesAllStyle; ++i)
@@ skipping 25 matching lines @@
         if (scopeSelector->match() == CSSSelector::Id)
             idScopes.add(scopeSelector->value().impl());
         else
             classScopes.add(scopeSelector->value().impl());
     }
     return true;
 }
 
 static bool ruleAdditionMightRequireDocumentStyleRecalc(StyleRuleBase* rule)
 {
-    // This funciton is conservative. We only return false when we know that
+    // This function is conservative. We only return false when we know that
     // the added @rule can't require style recalcs.
     switch (rule->type()) {
     case StyleRule::Import: // Whatever we import should do its own analysis, we don't need to invalidate the document here!
     case StyleRule::Page: // Page rules apply only during printing, we force a full-recalc before printing.
         return false;
 
     case StyleRule::Media: // If the media rule doesn't apply, we could avoid recalc.
     case StyleRule::FontFace: // If the fonts aren't in use, we could avoid recalc.
     case StyleRule::Supports: // If we evaluated the supports-clause we could avoid recalc.
     case StyleRule::Viewport: // If the viewport doesn't match, we could avoid recalcing.
-    case StyleRule::Keyframes: // If the animation doesn't match an element, we could avoid recalc.
         return true;
 
     // These should all be impossible to reach:
     case StyleRule::Charset:
     case StyleRule::Keyframe:
     case StyleRule::Namespace:
     case StyleRule::Style:
+    case StyleRule::Keyframes:
         break;
     }
     ASSERT_NOT_REACHED();
     return true;
 }
 
 void StyleSheetInvalidationAnalysis::analyzeStyleSheet(StyleSheetContents* styleSheetContents)
 {
     // Updating the style on the shadow DOM for image fallback content can bring us here when imports
     // are still getting loaded in the main document. Just need to exit early as we will return here
@@ skipping 12 matching lines @@
             return;
     }
 
     if (m_treeScope->rootNode().isShadowRoot())
         return;
 
     const HeapVector<Member<StyleRuleBase>>& rules = styleSheetContents->childRules();
     for (unsigned i = 0; i < rules.size(); i++) {
         StyleRuleBase* rule = rules[i].get();
         if (!rule->isStyleRule()) {
+            if (rule->type() == StyleRule::Keyframes) {
+                m_addsKeyframes = true;
+                continue;
+            }
             if (ruleAdditionMightRequireDocumentStyleRecalc(rule)) {
                 m_dirtiesAllStyle = true;
                 return;
             }
             continue;
         }
         StyleRule* styleRule = toStyleRule(rule);
         if (!determineSelectorScopes(styleRule->selectorList(), m_idScopes, m_classScopes)) {
             m_dirtiesAllStyle = true;
             return;
@@ skipping 12 matching lines @@
         if (classScopes.contains(classNames[i].impl()))
             return true;
     }
     return false;
 }
 
 void StyleSheetInvalidationAnalysis::invalidateStyle()
 {
     ASSERT(!m_dirtiesAllStyle);
 
+    if (m_addsKeyframes)
+        m_treeScope->document().styleEngine().keyframesRulesAdded();
+
     if (m_treeScope->rootNode().isShadowRoot()) {
         ContainerNode& shadowHost = toShadowRoot(m_treeScope->rootNode()).host();
         shadowHost.setNeedsStyleRecalc(SubtreeStyleChange, StyleChangeReasonForTracing::create(StyleChangeReason::StyleSheetChange));
         return;
     }
 
     if (m_idScopes.isEmpty() && m_classScopes.isEmpty())
         return;
     Element* element = ElementTraversal::firstWithin(m_treeScope->document());
     while (element) {
         if (elementMatchesSelectorScopes(element, m_idScopes, m_classScopes)) {
             element->setNeedsStyleRecalc(SubtreeStyleChange, StyleChangeReasonForTracing::create(StyleChangeReason::StyleSheetChange));
             // The whole subtree is now invalidated, we can skip to the next sibling.
             element = ElementTraversal::nextSkippingChildren(*element);
             continue;
         }
         element = ElementTraversal::next(*element);
     }
 }
 
 } // namespace blink