diff --git a/sky/engine/core/dom/Document.cpp b/sky/engine/core/dom/Document.cpp
index feeb300..3180121 100644
--- a/sky/engine/core/dom/Document.cpp
+++ b/sky/engine/core/dom/Document.cpp
@@ -292,11 +292,6 @@
 
     m_lifecycle.advanceTo(DocumentLifecycle::Inactive);
 
-    // Since CSSFontSelector requires Document::m_fetcher and StyleEngine owns
-    // CSSFontSelector, need to initialize m_styleEngine after initializing
-    // m_fetcher.
-    m_styleEngine = StyleEngine::create(*this);
-
 #ifndef NDEBUG
     liveDocumentSet().add(this);
 #endif
@@ -1230,11 +1225,14 @@
 
 StyleResolver* Document::styleResolver() const
 {
+    if (!isActive())
+        return 0;
     return m_styleEngine->resolver();
 }
 
 StyleResolver& Document::ensureStyleResolver() const
 {
+    ASSERT(isActive());
     return m_styleEngine->ensureResolver();
 }
 
@@ -1247,6 +1245,8 @@
 {
     ASSERT(m_lifecycle.state() == DocumentLifecycle::Inactive);
 
+    m_styleEngine = StyleEngine::create(*this);
+
     m_renderView = new RenderView(this);
     setRenderer(m_renderView);
 
@@ -1284,6 +1284,7 @@
     ContainerNode::detach(context);
 
     m_styleEngine->didDetach();
+    m_styleEngine = nullptr;
 
     // This is required, as our LocalFrame might delete itself as soon as it detaches
     // us. However, this violates Node::detach() semantics, as it's never
diff --git a/sky/engine/core/dom/StyleEngine.cpp b/sky/engine/core/dom/StyleEngine.cpp
index 1e3764c..79af43e 100644
--- a/sky/engine/core/dom/StyleEngine.cpp
+++ b/sky/engine/core/dom/StyleEngine.cpp
@@ -44,9 +44,7 @@
 
 StyleEngine::StyleEngine(Document& document)
     : m_document(&document)
-    , m_isMaster(!document.importsController() || document.importsController()->master() == &document)
     , m_documentStyleSheetCollection(StyleSheetCollection::create(document))
-    , m_documentScopeDirty(true)
     , m_ignorePendingStylesheets(false)
     // We don't need to create CSSFontSelector for imported document or
     // HTMLTemplateElement's document, because those documents have no frame.
@@ -80,16 +78,6 @@
     m_scopedStyleResolvers.clear();
 }
 
-inline Document* StyleEngine::master()
-{
-    if (isMaster())
-        return m_document;
-    HTMLImportsController* import = document().importsController();
-    if (!import) // Document::import() can return null while executing its destructor.
-        return 0;
-    return import->master();
-}
-
 const Vector<RefPtr<CSSStyleSheet>>& StyleEngine::activeAuthorStyleSheetsFor(TreeScope& treeScope)
 {
     if (treeScope == m_document)
@@ -191,10 +179,9 @@
 
 void StyleEngine::updateActiveStyleSheets()
 {
-    ASSERT(isMaster());
-    ASSERT(!document().inStyleRecalc());
+    ASSERT(!m_document->inStyleRecalc());
 
-    if (!document().isActive())
+    if (!m_document->isActive())
         return;
 
     documentStyleSheetCollection()->updateActiveStyleSheets(this);
@@ -214,7 +201,6 @@
     m_activeTreeScopes.removeAll(treeScopesRemoved);
 
     m_dirtyTreeScopes.clear();
-    m_documentScopeDirty = false;
 }
 
 void StyleEngine::didRemoveShadowRoot(ShadowRoot* shadowRoot)
@@ -226,8 +212,6 @@
 
 void StyleEngine::appendActiveAuthorStyleSheets()
 {
-    ASSERT(isMaster());
-
     m_resolver->appendAuthorStyleSheets(documentStyleSheetCollection()->activeAuthorStyleSheets());
 
     TreeScopeSet::iterator begin = m_activeTreeScopes.begin();
@@ -245,7 +229,7 @@
     // which is not in a frame. Code which hits this should have checked
     // Document::isActive() before calling into code which could get here.
 
-    ASSERT(document().frame());
+    ASSERT(m_document->frame());
 
     m_resolver = adoptPtr(new StyleResolver(*m_document));
     addScopedStyleResolver(&m_document->ensureScopedStyleResolver());
@@ -255,8 +239,7 @@
 
 void StyleEngine::clearResolver()
 {
-    ASSERT(!document().inStyleRecalc());
-    ASSERT(isMaster() || !m_resolver);
+    ASSERT(!m_document->inStyleRecalc());
 
     for (ScopedStyleResolverSet::iterator it = m_scopedStyleResolvers.begin(); it != m_scopedStyleResolvers.end(); ++it)
         const_cast<TreeScope&>((*it)->treeScope()).clearScopedStyleResolver();
@@ -264,12 +247,6 @@
     m_resolver.clear();
 }
 
-void StyleEngine::clearMasterResolver()
-{
-    if (Document* master = this->master())
-        master->styleEngine()->clearResolver();
-}
-
 unsigned StyleEngine::resolverAccessCount() const
 {
     return m_resolver ? m_resolver->accessCount() : 0;
@@ -282,15 +259,9 @@
 
 void StyleEngine::resolverChanged()
 {
-    if (!isMaster()) {
-        if (Document* master = this->master())
-            master->styleResolverChanged();
-        return;
-    }
-
     // Don't bother updating, since we haven't loaded all our style info yet
     // and haven't calculated the style selector for the first time.
-    if (!document().isActive()) {
+    if (!m_document->isActive()) {
         clearResolver();
         return;
     }
@@ -310,7 +281,7 @@
 {
     // FIXME: we should not update generic font family settings when
     // document is inactive.
-    ASSERT(document().isActive());
+    ASSERT(m_document->isActive());
 
     if (!m_fontSelector)
         return;
@@ -334,21 +305,12 @@
 
 void StyleEngine::markTreeScopeDirty(TreeScope& scope)
 {
-    if (scope == m_document) {
-        markDocumentDirty();
+    // TODO(esprehn): Make document not special.
+    if (scope == m_document)
         return;
-    }
-
     m_dirtyTreeScopes.add(&scope);
 }
 
-void StyleEngine::markDocumentDirty()
-{
-    m_documentScopeDirty = true;
-    if (document().importLoader())
-        document().importsController()->master()->styleEngine()->markDocumentDirty();
-}
-
 PassRefPtr<CSSStyleSheet> StyleEngine::createSheet(Element* e, const String& text)
 {
     RefPtr<CSSStyleSheet> styleSheet;
@@ -391,12 +353,9 @@
 
 void StyleEngine::fontsNeedUpdate(CSSFontSelector*)
 {
-    if (!document().isActive())
-        return;
-
     if (m_resolver)
         m_resolver->invalidateMatchedPropertiesCache();
-    document().setNeedsStyleRecalc(SubtreeStyleChange);
+    m_document->setNeedsStyleRecalc(SubtreeStyleChange);
 }
 
 }
diff --git a/sky/engine/core/dom/StyleEngine.h b/sky/engine/core/dom/StyleEngine.h
index e59a50c..9be10a3 100644
--- a/sky/engine/core/dom/StyleEngine.h
+++ b/sky/engine/core/dom/StyleEngine.h
@@ -68,9 +68,7 @@
 
     ~StyleEngine();
 
-#if !ENABLE(OILPAN)
     void detachFromDocument();
-#endif
 
     const Vector<RefPtr<CSSStyleSheet>>& activeAuthorStyleSheetsFor(TreeScope&);
 
@@ -105,7 +103,6 @@
 
     bool hasResolver() const { return m_resolver.get(); }
     void clearResolver();
-    void clearMasterResolver();
 
     CSSFontSelector* fontSelector() { return m_fontSelector.get(); }
     void removeFontFaceRules(const Vector<RawPtr<const StyleRuleFontFace> >&);
@@ -117,8 +114,6 @@
     void resolverChanged();
     unsigned resolverAccessCount() const;
 
-    void markDocumentDirty();
-
     PassRefPtr<CSSStyleSheet> createSheet(Element*, const String& text);
     void removeSheet(StyleSheetContents*);
 
@@ -139,10 +134,6 @@
 
     void markTreeScopeDirty(TreeScope&);
 
-    bool isMaster() const { return m_isMaster; }
-    Document* master();
-    Document& document() const { return *m_document; }
-
     typedef ListHashSet<TreeScope*, 16> TreeScopeSet;
     static void insertTreeScopeInDocumentOrder(TreeScopeSet&, TreeScope*);
 
@@ -159,7 +150,6 @@
     }
 
     RawPtr<Document> m_document;
-    bool m_isMaster;
 
     // TODO(esprehn): Remove special separate collection for document.
     OwnPtr<StyleSheetCollection> m_documentStyleSheetCollection;
@@ -169,7 +159,6 @@
     typedef HashSet<RawPtr<const ScopedStyleResolver> > ScopedStyleResolverSet;
     ScopedStyleResolverSet m_scopedStyleResolvers;
 
-    bool m_documentScopeDirty;
     TreeScopeSet m_dirtyTreeScopes;
     TreeScopeSet m_activeTreeScopes;
 
diff --git a/sky/engine/core/dom/StyleSheetCollection.cpp b/sky/engine/core/dom/StyleSheetCollection.cpp
index 4e99b28..9ffc0a3 100644
--- a/sky/engine/core/dom/StyleSheetCollection.cpp
+++ b/sky/engine/core/dom/StyleSheetCollection.cpp
@@ -85,7 +85,7 @@
 
     // TODO(esprehn): Remove special casing for Document.
     if (root.isDocumentNode()) {
-        engine->clearMasterResolver();
+        engine->clearResolver();
         // FIMXE: The following depends on whether StyleRuleFontFace was modified or not.
         // No need to always-clear font cache.
         engine->clearFontCache();
diff --git a/sky/engine/core/html/HTMLStyleElement.cpp b/sky/engine/core/html/HTMLStyleElement.cpp
index d7ce4d9..265fd75 100644
--- a/sky/engine/core/html/HTMLStyleElement.cpp
+++ b/sky/engine/core/html/HTMLStyleElement.cpp
@@ -51,7 +51,8 @@
     if (inDocument()) {
         ContainerNode* scopingNode = this->scopingNode();
         TreeScope& scope = scopingNode ? scopingNode->treeScope() : treeScope();
-        document().styleEngine()->removeStyleSheetCandidateNode(this, scopingNode, scope);
+        if (StyleEngine* styleEngine = document().styleEngine())
+            styleEngine->removeStyleSheetCandidateNode(this, scopingNode, scope);
     }
 
     if (m_sheet)
@@ -76,15 +77,17 @@
 void HTMLStyleElement::insertedInto(ContainerNode* insertionPoint)
 {
     HTMLElement::insertedInto(insertionPoint);
-    document().styleEngine()->addStyleSheetCandidateNode(this, false);
-    process();
+    if (inActiveDocument()) {
+        document().styleEngine()->addStyleSheetCandidateNode(this, false);
+        process();
+    }
 }
 
 void HTMLStyleElement::removedFrom(ContainerNode* insertionPoint)
 {
     HTMLElement::removedFrom(insertionPoint);
 
-    if (!insertionPoint->inDocument())
+    if (!insertionPoint->inActiveDocument())
         return;
 
     ShadowRoot* scopingNode = containingShadowRoot();
@@ -117,7 +120,7 @@
 
 ContainerNode* HTMLStyleElement::scopingNode()
 {
-    if (!inDocument())
+    if (!inActiveDocument())
         return 0;
 
     if (isInShadowTree())
@@ -134,7 +137,7 @@
 
 void HTMLStyleElement::process()
 {
-    if (!inDocument())
+    if (!inActiveDocument())
         return;
 
     TRACE_EVENT0("blink", "StyleElement::process");
diff --git a/sky/engine/core/page/Page.cpp b/sky/engine/core/page/Page.cpp
index ae9af7e..af0be64 100644
--- a/sky/engine/core/page/Page.cpp
+++ b/sky/engine/core/page/Page.cpp
@@ -223,7 +223,7 @@
         }
         break;
     case SettingsDelegate::FontFamilyChange:
-        if (mainFrame()->document())
+        if (mainFrame()->document() && mainFrame()->document()->isActive())
             mainFrame()->document()->styleEngine()->updateGenericFontFamilySettings();
         setNeedsRecalcStyleInAllFrames();
         break;