Simplify calls for scale factor

content/browser/renderer_host/render_widget_host_view_mac.h

Index: content/browser/renderer_host/render_widget_host_view_mac.h
diff --git a/content/browser/renderer_host/render_widget_host_view_mac.h b/content/browser/renderer_host/render_widget_host_view_mac.h
index 16f5f375dac464aa4099770a2e39838be2087995..5f4179c2e38267b8b96d23a241b450afceb40902 100644
--- a/content/browser/renderer_host/render_widget_host_view_mac.h
+++ b/content/browser/renderer_host/render_widget_host_view_mac.h
@@ -431,9 +431,6 @@ class CONTENT_EXPORT RenderWidgetHostViewMac
 
   int window_number() const;
 
-  // The scale factor for the screen that the view is currently on.
-  float ViewScaleFactor() const;
-
   // Update properties, such as the scale factor for the backing store
   // and for any CALayers, and the screen color profile.
   void UpdateBackingStoreProperties();
@@ -553,6 +550,9 @@ class CONTENT_EXPORT RenderWidgetHostViewMac
   // Whether a request to flush input has been issued.
   bool needs_flush_input_;
 
+  // Device scale factor. Updated when the display metric is updated.
+  float device_scale_factor_;
+
   // Factory used to safely scope delayed calls to ShutdownHost().
   base::WeakPtrFactory<RenderWidgetHostViewMac> weak_factory_;