Scale scrollbar in use-zoom-for-dsf mode

third_party/WebKit/Source/platform/scroll/Scrollbar.h

Index: third_party/WebKit/Source/platform/scroll/Scrollbar.h
diff --git a/third_party/WebKit/Source/platform/scroll/Scrollbar.h b/third_party/WebKit/Source/platform/scroll/Scrollbar.h
index 072e38c04e9cc7c16a65e293cd26a0a0c2cf5e7f..4256eb3fdcc37a7553d7a0ae93a7aa47b1b404d4 100644
--- a/third_party/WebKit/Source/platform/scroll/Scrollbar.h
+++ b/third_party/WebKit/Source/platform/scroll/Scrollbar.h
@@ -38,6 +38,7 @@
 namespace blink {
 
 class GraphicsContext;
+class HostWindow;
 class IntRect;
 class PlatformGestureEvent;
 class PlatformMouseEvent;
@@ -47,7 +48,7 @@ class ScrollbarTheme;
 
 class PLATFORM_EXPORT Scrollbar : public Widget, public ScrollbarThemeClient {
 public:
-    static PassRefPtrWillBeRawPtr<Scrollbar> create(ScrollableArea*, ScrollbarOrientation, ScrollbarControlSize);
+    static PassRefPtrWillBeRawPtr<Scrollbar> create(ScrollableArea*, ScrollbarOrientation, ScrollbarControlSize, HostWindow*);
 
     // Theme object ownership remains with the caller and it must outlive the scrollbar.
     static PassRefPtrWillBeRawPtr<Scrollbar> createForTesting(ScrollableArea*, ScrollbarOrientation, ScrollbarControlSize, ScrollbarTheme*);
@@ -93,6 +94,8 @@ public:
     bool enabled() const override { return m_enabled; }
     void setEnabled(bool) override;
 
+    int scrollbarThickness() const;
+
     // Called by the ScrollableArea when the scroll offset changes.
     void offsetDidChange();
 
@@ -177,7 +180,7 @@ public:
     DECLARE_VIRTUAL_TRACE();
 
 protected:
-    Scrollbar(ScrollableArea*, ScrollbarOrientation, ScrollbarControlSize, ScrollbarTheme* = 0);
+    Scrollbar(ScrollableArea*, ScrollbarOrientation, ScrollbarControlSize, HostWindow* = 0, ScrollbarTheme* = 0);
 
     void autoscrollTimerFired(Timer<Scrollbar>*);
     void startTimerIfNeeded(double delay);
@@ -190,6 +193,7 @@ protected:
     ScrollbarOrientation m_orientation;
     ScrollbarControlSize m_controlSize;
     ScrollbarTheme& m_theme;
+    HostWindow* m_hostWindow;
 
     int m_visibleSize;
     int m_totalSize;