[DevTools] Use device metrics emulation implemented in content.

Source/core/page/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 171 matching lines @@
     , m_isTrackingRepaints(false)
     , m_shouldUpdateWhileOffscreen(true)
     , m_deferSetNeedsLayouts(0)
     , m_setNeedsLayoutWasDeferred(false)
     , m_scrollCorner(0)
     , m_shouldAutoSize(false)
     , m_inAutoSize(false)
     , m_didRunAutosize(false)
     , m_hasSoftwareFilters(false)
     , m_visibleContentScaleFactor(1)
+    , m_inputEventsScaleFactorForEmulation(1)
     , m_partialLayout()
 {
     ASSERT(m_frame);
     init();
 
     if (!isMainFrame())
         return;
 
     ScrollableArea::setVerticalScrollElasticity(ScrollElasticityAllowed);
     ScrollableArea::setHorizontalScrollElasticity(ScrollElasticityAllowed);
@@ skipping 2340 matching lines @@
 
 void FrameView::setVisibleContentScaleFactor(float visibleContentScaleFactor)
 {
     if (m_visibleContentScaleFactor == visibleContentScaleFactor)
         return;
 
     m_visibleContentScaleFactor = visibleContentScaleFactor;
     updateScrollbars(scrollOffset());
 }
 
+void FrameView::setInputEventsScaleFactorForEmulation(float contentScaleFactor)
+{
+    if (m_inputEventsScaleFactorForEmulation == contentScaleFactor)
+        return;
+
+    m_inputEventsScaleFactorForEmulation = contentScaleFactor;
+}
+
+float FrameView::inputEventsScaleFactor() const
+{
+    return visibleContentScaleFactor() * m_inputEventsScaleFactorForEmulation;
+}
+
 bool FrameView::scrollbarsCanBeActive() const
 {
     if (m_frame->view() != this)
         return false;
 
     return !!m_frame->document();
 }
 
 ScrollableArea* FrameView::enclosingScrollableArea() const
 {
@@ skipping 844 matching lines @@
         return frame().document()->existingAXObjectCache();
     return 0;
 }
 
 bool FrameView::isMainFrame() const
 {
     return m_frame->page() && m_frame->page()->mainFrame() == m_frame;
 }
 
 } // namespace WebCore