Current work-in-progress crbug.com/567021

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 d1a185bbf8b3af07f744df0a7516d64a3bb4c7c7..ab41a6aca6ca3924263a403493c1e49b729336fe 100644
--- a/third_party/WebKit/Source/core/dom/TreeScopeStyleSheetCollection.cpp
+++ b/third_party/WebKit/Source/core/dom/TreeScopeStyleSheetCollection.cpp
@@ -26,10 +26,10 @@
 
 #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"
@@ -40,131 +40,32 @@ namespace blink {
 
 TreeScopeStyleSheetCollection::TreeScopeStyleSheetCollection(TreeScope& treeScope)
     : m_treeScope(treeScope)
-    , m_hadActiveLoadingStylesheet(false)
 {
 }
 
 void TreeScopeStyleSheetCollection::addStyleSheetCandidateNode(Node* node)
 {
-    if (!node->inShadowIncludingDocument())
-        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;
-}
-
-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;
-    unsigned newStylesheetCount = newStyleSheets.size();
-    for (unsigned i = 0; i < newStylesheetCount; ++i) {
-        if (newStyleSheets[i]->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 (unsigned i = 0; i < sheets.size(); ++i) {
-        DCHECK(sheets[i]);
-        if (sheets[i]->hasFontFaceRule()) {
-            // FIXME: We don't need this for styles in shadow tree.
-            sheets[i]->findFontFaceRules(fontFaceRules);
-            hasFontFaceRule = true;
-        }
-    }
-    return hasFontFaceRule;
+    if (node->inShadowIncludingDocument())
+        m_styleSheetCandidateNodes.add(node);
 }
 
-void TreeScopeStyleSheetCollection::analyzeStyleSheetChange(StyleResolverUpdateMode updateMode, const StyleSheetCollection& newCollection, StyleSheetChange& change)
-{
-    if (activeLoadingStyleSheetLoaded(newCollection.activeAuthorStyleSheets()))
-        return;
-
-    if (updateMode != AnalyzedStyleUpdate)
-        return;
-
-    // Find out which stylesheets are new.
-    HeapVector<Member<StyleSheetContents>> addedSheets;
-    if (m_activeAuthorStyleSheets.size() <= newCollection.activeAuthorStyleSheets().size()) {
-        change.styleResolverUpdateType = compareStyleSheets(m_activeAuthorStyleSheets, newCollection.activeAuthorStyleSheets(), addedSheets);
-    } else {
-        StyleResolverUpdateType updateType = compareStyleSheets(newCollection.activeAuthorStyleSheets(), 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()
+bool TreeScopeStyleSheetCollection::mediaQueryAffectingValueChanged()
 {
+    bool needsActiveStyleUpdate = false;
     for (size_t i = 0; i < m_activeAuthorStyleSheets.size(); ++i) {
-        StyleSheetContents* contents = m_activeAuthorStyleSheets[i]->contents();
+        if (m_activeAuthorStyleSheets[i].first->mediaQueries())
+            needsActiveStyleUpdate = true;
+        StyleSheetContents* contents = m_activeAuthorStyleSheets[i].first->contents();
         if (contents->hasMediaQueries())
             contents->clearRuleSet();
     }
+    return needsActiveStyleUpdate;
+}
+
+void TreeScopeStyleSheetCollection::applyActiveStyleSheetChanges(StyleSheetCollection& newCollection)
+{
+    applyRuleSetChanges(document().styleEngine(), treeScope(), activeAuthorStyleSheets(), newCollection.activeAuthorStyleSheets());
+    newCollection.swap(*this);
 }
 
 DEFINE_TRACE(TreeScopeStyleSheetCollection)