Collect active stylesheets and and apply asynchronously.

third_party/WebKit/Source/core/dom/TreeScopeStyleSheetCollection.cpp

Index: third_party/WebKit/Source/core/dom/TreeScopeStyleSheetCollection.cpp
diff --git a/third_party/WebKit/Source/core/dom/TreeScopeStyleSheetCollection.cpp b/third_party/WebKit/Source/core/dom/TreeScopeStyleSheetCollection.cpp
index a64330698a590fa62ffe8da209d914a5272f575c..918824798ed10537f1849443e14cd12541843d22 100644
--- a/third_party/WebKit/Source/core/dom/TreeScopeStyleSheetCollection.cpp
+++ b/third_party/WebKit/Source/core/dom/TreeScopeStyleSheetCollection.cpp
@@ -28,10 +28,10 @@
 
 #include "core/dom/TreeScopeStyleSheetCollection.h"
 
+#include "core/css/ActiveStyleSheets.h"
 #include "core/css/CSSStyleSheet.h"
 #include "core/css/StyleRuleImport.h"
 #include "core/css/StyleSheetContents.h"
-#include "core/css/invalidation/StyleSheetInvalidationAnalysis.h"
 #include "core/css/resolver/StyleResolver.h"
 #include "core/dom/Element.h"
 #include "core/dom/StyleEngine.h"
@@ -42,139 +42,31 @@ namespace blink {
 
 TreeScopeStyleSheetCollection::TreeScopeStyleSheetCollection(
     TreeScope& treeScope)
-    : m_treeScope(treeScope), m_hadActiveLoadingStylesheet(false) {}
+    : m_treeScope(treeScope) {}
 
 void TreeScopeStyleSheetCollection::addStyleSheetCandidateNode(Node& node) {
-  if (!node.isConnected())
-    return;
-
-  m_styleSheetCandidateNodes.add(&node);
-}
-
-TreeScopeStyleSheetCollection::StyleResolverUpdateType
-TreeScopeStyleSheetCollection::compareStyleSheets(
-    const HeapVector<Member<CSSStyleSheet>>& oldStyleSheets,
-    const HeapVector<Member<CSSStyleSheet>>& newStylesheets,
-    HeapVector<Member<StyleSheetContents>>& addedSheets) {
-  unsigned newStyleSheetCount = newStylesheets.size();
-  unsigned oldStyleSheetCount = oldStyleSheets.size();
-  DCHECK_GE(newStyleSheetCount, oldStyleSheetCount);
-
-  if (!newStyleSheetCount)
-    return Reconstruct;
-
-  unsigned newIndex = 0;
-  for (unsigned oldIndex = 0; oldIndex < oldStyleSheetCount; ++oldIndex) {
-    while (oldStyleSheets[oldIndex] != newStylesheets[newIndex]) {
-      addedSheets.append(newStylesheets[newIndex]->contents());
-      if (++newIndex == newStyleSheetCount)
-        return Reconstruct;
-    }
-    if (++newIndex == newStyleSheetCount)
-      return Reconstruct;
-  }
-  bool hasInsertions = !addedSheets.isEmpty();
-  while (newIndex < newStyleSheetCount) {
-    addedSheets.append(newStylesheets[newIndex]->contents());
-    ++newIndex;
-  }
-  // If all new sheets were added at the end of the list we can just add them to
-  // existing StyleResolver.  If there were insertions we need to re-add all the
-  // stylesheets so rules are ordered correctly.
-  return hasInsertions ? Reset : Additive;
+  if (node.isConnected())
+    m_styleSheetCandidateNodes.add(&node);
 }
 
-bool TreeScopeStyleSheetCollection::activeLoadingStyleSheetLoaded(
-    const HeapVector<Member<CSSStyleSheet>>& newStyleSheets) {
-  // StyleSheets of <style> elements that @import stylesheets are active but
-  // loading. We need to trigger a full recalc when such loads are done.
-  bool hasActiveLoadingStylesheet = false;
-  for (const auto& sheet : newStyleSheets) {
-    if (sheet->isLoading())
-      hasActiveLoadingStylesheet = true;
-  }
-  if (m_hadActiveLoadingStylesheet && !hasActiveLoadingStylesheet) {
-    m_hadActiveLoadingStylesheet = false;
-    return true;
-  }
-  m_hadActiveLoadingStylesheet = hasActiveLoadingStylesheet;
-  return false;
-}
-
-static bool findFontFaceRulesFromStyleSheetContents(
-    const HeapVector<Member<StyleSheetContents>>& sheets,
-    HeapVector<Member<const StyleRuleFontFace>>& fontFaceRules) {
-  bool hasFontFaceRule = false;
-
-  for (const auto& sheet : sheets) {
-    DCHECK(sheet);
-    if (sheet->hasFontFaceRule()) {
-      // FIXME: We don't need this for styles in shadow tree.
-      sheet->findFontFaceRules(fontFaceRules);
-      hasFontFaceRule = true;
-    }
-  }
-  return hasFontFaceRule;
-}
-
-void TreeScopeStyleSheetCollection::analyzeStyleSheetChange(
-    StyleResolverUpdateMode updateMode,
-    const HeapVector<Member<CSSStyleSheet>>& newActiveAuthorStyleSheets,
-    StyleSheetChange& change) {
-  if (activeLoadingStyleSheetLoaded(newActiveAuthorStyleSheets))
-    return;
-
-  if (updateMode != AnalyzedStyleUpdate)
-    return;
-
-  // Find out which stylesheets are new.
-  HeapVector<Member<StyleSheetContents>> addedSheets;
-  if (m_activeAuthorStyleSheets.size() <= newActiveAuthorStyleSheets.size()) {
-    change.styleResolverUpdateType = compareStyleSheets(
-        m_activeAuthorStyleSheets, newActiveAuthorStyleSheets, addedSheets);
-  } else {
-    StyleResolverUpdateType updateType = compareStyleSheets(
-        newActiveAuthorStyleSheets, m_activeAuthorStyleSheets, addedSheets);
-    if (updateType != Additive) {
-      change.styleResolverUpdateType = updateType;
-    } else {
-      change.styleResolverUpdateType = Reset;
-      // If @font-face is removed, needs full style recalc.
-      if (findFontFaceRulesFromStyleSheetContents(addedSheets,
-                                                  change.fontFaceRulesToRemove))
-        return;
-    }
-  }
-
-  // FIXME: If styleResolverUpdateType is Reconstruct, we should return early
-  // here since we need to recalc the whole document. It's wrong to use
-  // StyleSheetInvalidationAnalysis since it only looks at the addedSheets.
-
-  // No point in doing the analysis work if we're just going to recalc the whole
-  // document anyways.  This needs to be done after the compareStyleSheets calls
-  // above to ensure we don't throw away the StyleResolver if we don't need to.
-  if (document().hasPendingForcedStyleRecalc())
-    return;
-
-  // If we are already parsing the body and so may have significant amount of
-  // elements, put some effort into trying to avoid style recalcs.
-  if (!document().body() || document().hasNodesWithPlaceholderStyle())
-    return;
-  StyleSheetInvalidationAnalysis invalidationAnalysis(*m_treeScope,
-                                                      addedSheets);
-  if (invalidationAnalysis.dirtiesAllStyle())
-    return;
-  invalidationAnalysis.invalidateStyle();
-  change.requiresFullStyleRecalc = false;
-  return;
-}
-
-void TreeScopeStyleSheetCollection::clearMediaQueryRuleSetStyleSheets() {
-  for (const auto& sheet : m_activeAuthorStyleSheets) {
-    StyleSheetContents* contents = sheet->contents();
+bool TreeScopeStyleSheetCollection::mediaQueryAffectingValueChanged() {
+  bool needsActiveStyleUpdate = false;
+  for (const auto& activeSheet : m_activeAuthorStyleSheets) {
+    if (activeSheet.first->mediaQueries())
+      needsActiveStyleUpdate = true;
+    StyleSheetContents* contents = activeSheet.first->contents();
     if (contents->hasMediaQueries())
       contents->clearRuleSet();
   }
+  return needsActiveStyleUpdate;
+}
+
+void TreeScopeStyleSheetCollection::applyActiveStyleSheetChanges(
+    StyleSheetCollection& newCollection) {
+  document().styleEngine().applyRuleSetChanges(
+      treeScope(), activeAuthorStyleSheets(),
+      newCollection.activeAuthorStyleSheets());
+  newCollection.swap(*this);
 }
 
 DEFINE_TRACE(TreeScopeStyleSheetCollection) {