Don't walk treescopes in updateActiveStyleSheets until the resolver exists.

sky/engine/core/dom/StyleSheetCollection.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
@@ skipping 12 matching lines @@
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #include "sky/engine/config.h"
 #include "sky/engine/core/dom/StyleSheetCollection.h"
 
 #include "sky/engine/core/css/CSSStyleSheet.h"
 #include "sky/engine/core/css/resolver/StyleResolver.h"
 #include "sky/engine/core/dom/Document.h"
-#include "sky/engine/core/dom/StyleEngine.h"
 #include "sky/engine/core/dom/shadow/ShadowRoot.h"
 #include "sky/engine/core/dom/TreeScope.h"
 #include "sky/engine/core/html/HTMLStyleElement.h"
 
 namespace blink {
 
 StyleSheetCollection::StyleSheetCollection(TreeScope& treeScope)
     : m_treeScope(treeScope)
     , m_needsUpdate(true)
 {
@@ skipping 18 matching lines @@
 
 void StyleSheetCollection::collectStyleSheets(Vector<RefPtr<CSSStyleSheet>>& sheets)
 {
     for (Node* node : m_styleSheetCandidateNodes) {
         ASSERT(isHTMLStyleElement(*node));
         if (CSSStyleSheet* sheet = toHTMLStyleElement(node)->sheet())
             sheets.append(sheet);
     }
 }
 
-void StyleSheetCollection::updateActiveStyleSheets(StyleEngine* engine)
+void StyleSheetCollection::updateActiveStyleSheets(StyleResolver& resolver)
 {
-    // TODO(esprehn): We need to check if the resolver exists otherwise style
-    // doesn't get computed right. We should figure out why.
-    if (!m_needsUpdate && engine->resolver())
+    if (!m_needsUpdate)
         return;
 
     Vector<RefPtr<CSSStyleSheet>> candidateSheets;
     collectStyleSheets(candidateSheets);
 
+    m_treeScope.scopedStyleResolver().resetAuthorStyle();
+    resolver.removePendingAuthorStyleSheets(m_activeAuthorStyleSheets);
+    resolver.lazyAppendAuthorStyleSheets(0, candidateSheets);
+
     Node& root = m_treeScope.rootNode();
 
-    // TODO(esprehn): Remove special casing for Document.
-    if (root.isDocumentNode()) {
-        engine->clearResolver();
-        // FIMXE: The following depends on whether StyleRuleFontFace was modified or not.
-        // No need to always-clear font cache.
-        engine->clearFontCache();
-    } else if (StyleResolver* styleResolver = engine->resolver()) {
-        // We should not destroy StyleResolver when we find any stylesheet update in a shadow tree.
-        // In this case, we will reset rulesets created from style elements in the shadow tree.
-        m_treeScope.scopedStyleResolver().resetAuthorStyle();
-        styleResolver->removePendingAuthorStyleSheets(m_activeAuthorStyleSheets);
-        styleResolver->lazyAppendAuthorStyleSheets(0, candidateSheets);
-    }
-
     // TODO(esprehn): We should avoid subtree recalcs in sky when rules change
     // and only recalc specific tree scopes.
     root.setNeedsStyleRecalc(SubtreeStyleChange);
 
     // TODO(esprehn): We should use LocalStyleChange, :host rule changes
     // can only impact the host directly as Sky has no descendant selectors.
     if (root.isShadowRoot())
         toShadowRoot(root).host()->setNeedsStyleRecalc(SubtreeStyleChange);
 
     m_activeAuthorStyleSheets.swap(candidateSheets);
     m_needsUpdate = false;
 }
 
 }