Rendering text to a canvas in a frame-less document.

third_party/WebKit/Source/core/dom/StyleEngine.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, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) Research In Motion Limited 2010-2011. All rights reserved.
@@ skipping 43 matching lines @@
 #include "platform/fonts/FontCache.h"
 
 namespace blink {
 
 using namespace HTMLNames;
 
 StyleEngine::StyleEngine(Document& document)
     : m_document(&document)
     , m_isMaster(!document.importsController() || document.importsController()->master() == &document)
     , m_documentStyleSheetCollection(DocumentStyleSheetCollection::create(document))
-    // We don't need to create CSSFontSelector for imported document or
-    // HTMLTemplateElement's document, because those documents have no frame.
-    , m_fontSelector(document.frame() ? CSSFontSelector::create(&document) : nullptr)
 {
-    if (m_fontSelector)
-        m_fontSelector->registerForInvalidationCallbacks(this);
+    m_fontSelector = CSSFontSelector::create(m_document);
+    m_fontSelector->registerForInvalidationCallbacks(this);
 }
 
 StyleEngine::~StyleEngine()
 {
 }
 
 static bool isStyleElement(Node& node)
 {
     return isHTMLStyleElement(node) || isSVGStyleElement(node);
 }
@@ skipping 303 matching lines @@
     m_resolver->appendAuthorStyleSheets(documentStyleSheetCollection()->activeAuthorStyleSheets());
     for (TreeScope* treeScope : m_activeTreeScopes) {
         if (TreeScopeStyleSheetCollection* collection = m_styleSheetCollectionMap.get(treeScope))
             m_resolver->appendAuthorStyleSheets(collection->activeAuthorStyleSheets());
     }
     m_resolver->finishAppendAuthorStyleSheets();
 }
 
 void StyleEngine::createResolver()
 {
-    TRACE_EVENT1("blink", "StyleEngine::createResolver", "frame", document().frame());
-    // It is a programming error to attempt to resolve style on a Document
-    // which is not in a frame. Code which hits this should have checked
-    // Document::isActive() before calling into code which could get here.
-
-    DCHECK(document().frame());
-
     m_resolver = StyleResolver::create(*m_document);
 
     // A scoped style resolver for document will be created during
     // appendActiveAuthorStyleSheets if needed.
     appendActiveAuthorStyleSheets();
 }
 
 void StyleEngine::clearResolver()
 {
     DCHECK(!document().inStyleRecalc());
@@ skipping 432 matching lines @@
 
 DEFINE_TRACE_WRAPPERS(StyleEngine)
 {
     for (auto sheet : m_injectedAuthorStyleSheets) {
         visitor->traceWrappers(sheet);
     }
     visitor->traceWrappers(m_documentStyleSheetCollection);
 }
 
 } // namespace blink