| Index: Source/core/dom/Document.cpp | 
| diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp | 
| index f4cb2b31ea14ef492d5a84eb96492f62522d87be..f920a0a04589b4f19fecadc6b5ec84ea389a032f 100644 | 
| --- a/Source/core/dom/Document.cpp | 
| +++ b/Source/core/dom/Document.cpp | 
| @@ -5377,6 +5377,11 @@ void Document::didAssociateFormControlsTimerFired(Timer<Document>* timer) | 
| m_associatedFormControls.clear(); | 
| } | 
|  | 
| +float Document::devicePixelRatio() const | 
| +{ | 
| +    return m_frame ? m_frame->devicePixelRatio() : 1.0; | 
| +} | 
| + | 
| PassOwnPtr<LifecycleNotifier> Document::createLifecycleNotifier() | 
| { | 
| return DocumentLifecycleNotifier::create(this); | 
|  |