Paint scrollbars at device scale resolution.

third_party/WebKit/public/platform/WebScrollbarThemePainter.h

Index: third_party/WebKit/public/platform/WebScrollbarThemePainter.h
diff --git a/third_party/WebKit/public/platform/WebScrollbarThemePainter.h b/third_party/WebKit/public/platform/WebScrollbarThemePainter.h
index 268d94bbcdd675afb4f84970a8deaf3b898e1106..6563a6e65b533381525d75d541d02ed2601eef06 100644
--- a/third_party/WebKit/public/platform/WebScrollbarThemePainter.h
+++ b/third_party/WebKit/public/platform/WebScrollbarThemePainter.h
@@ -38,7 +38,7 @@ struct WebRect;
 
 class WebScrollbarThemePainter {
 public:
-    WebScrollbarThemePainter() : m_theme(0) { }
+    WebScrollbarThemePainter() : m_theme(0), m_deviceScaleFactor(1.0) { }
     WebScrollbarThemePainter(const WebScrollbarThemePainter& painter) { assign(painter); }
     virtual ~WebScrollbarThemePainter()
     {
@@ -65,7 +65,7 @@ public:
     BLINK_PLATFORM_EXPORT void paintThumb(WebCanvas*, const WebRect&);
 
 #if INSIDE_BLINK
-    BLINK_PLATFORM_EXPORT WebScrollbarThemePainter(ScrollbarTheme*, Scrollbar*);
+    BLINK_PLATFORM_EXPORT WebScrollbarThemePainter(ScrollbarTheme*, Scrollbar*, float deviceScaleFactor);
 #endif
 
 private:
@@ -80,6 +80,8 @@ private:
     // scrollbar (and not a WebScrollbar wrapper) due to static_casts for
     // LayoutScrollbar and pointer-based HashMap lookups for Lion scrollbars.
     WebPrivatePtr<Scrollbar> m_scrollbar;
+
+    float m_deviceScaleFactor;
 };
 
 } // namespace blink