Fix inspector overlay when use-zoom-for-dsf is enabled.

third_party/WebKit/Source/core/frame/FrameView.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Dirk Mueller <mueller@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
@@ skipping 3716 matching lines @@
 }
 
 IntRect FrameView::contentsToScreen(const IntRect& rect) const
 {
     HostWindow* window = getHostWindow();
     if (!window)
         return IntRect();
     return window->viewportToScreen(contentsToViewport(rect), this);
 }
 
+float FrameView::viewportToWindowScale() const
+{
+    return 1.f / getHostWindow()->windowToViewportScalar(1.f);
+}
+
 IntRect FrameView::soonToBeRemovedContentsToUnscaledViewport(const IntRect& rectInContents) const
 {
     IntRect rectInFrame = contentsToFrame(rectInContents);
     IntRect rectInRootFrame = convertToRootFrame(rectInFrame);
     return enclosingIntRect(m_frame->host()->visualViewport().mainViewToViewportCSSPixels(rectInRootFrame));
 }
 
 IntPoint FrameView::soonToBeRemovedUnscaledViewportToContents(const IntPoint& pointInViewport) const
 {
     IntPoint pointInRootFrame = flooredIntPoint(m_frame->host()->visualViewport().viewportCSSPixelsToRootFrame(pointInViewport));
@@ skipping 482 matching lines @@
     return m_subtreeThrottled || (m_hiddenForThrottling && m_crossOriginForThrottling);
 }
 
 LayoutBox& FrameView::boxForScrollControlPaintInvalidation() const
 {
     ASSERT(!layoutViewItem().isNull());
     return *layoutView();
 }
 
 } // namespace blink