Speculative fix for null m_documentLoader in restoreScrollPositionAndViewState.

third_party/WebKit/Source/core/loader/FrameLoader.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2008 Alp Toker <alp@atoker.com>
  * Copyright (C) Research In Motion Limited 2009. All rights reserved.
  * Copyright (C) 2011 Kris Jordan <krisjordan@gmail.com>
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ skipping 1100 matching lines @@
 }
 
 FrameLoadType FrameLoader::loadType() const
 {
     return m_loadType;
 }
 
 void FrameLoader::restoreScrollPositionAndViewState()
 {
     FrameView* view = m_frame->view();
-    if (!m_frame->page() || !view || !view->layoutViewportScrollableArea() || !m_currentItem || !m_stateMachine.committedFirstRealDocumentLoad())
+    if (!m_frame->page()
+        || !view
+        || !view->layoutViewportScrollableArea()
+        || !m_currentItem
+        || !m_stateMachine.committedFirstRealDocumentLoad()
+        || !documentLoader()) {
         return;
+    }
 
     if (!needsHistoryItemRestore(m_loadType))
         return;
 
     bool shouldRestoreScroll = m_currentItem->scrollRestorationType() != ScrollRestorationManual;
     bool shouldRestoreScale = m_currentItem->pageScaleFactor();
 
     // This tries to balance:
     //   1. restoring as soon as possible
     //   2. not overriding user scroll (TODO(majidvp): also respect user scale)
@@ skipping 414 matching lines @@
     // FIXME: We need a way to propagate insecure requests policy flags to
     // out-of-process frames. For now, we'll always use default behavior.
     if (!parentFrame->isLocalFrame())
         return nullptr;
 
     ASSERT(toLocalFrame(parentFrame)->document());
     return toLocalFrame(parentFrame)->document()->insecureNavigationsToUpgrade();
 }
 
 } // namespace blink