GetScaleFactorForNativeView should return scale factor in float

content/browser/web_contents/aura/overscroll_navigation_overlay.cc

Index: content/browser/web_contents/aura/overscroll_navigation_overlay.cc
diff --git a/content/browser/web_contents/aura/overscroll_navigation_overlay.cc b/content/browser/web_contents/aura/overscroll_navigation_overlay.cc
index 0d66ff1c8667394f69bc81e889c04056ad54294f..226f97be32c87af0b59345799dfb5e4dbc75ab0b 100644
--- a/content/browser/web_contents/aura/overscroll_navigation_overlay.cc
+++ b/content/browser/web_contents/aura/overscroll_navigation_overlay.cc
@@ -12,6 +12,7 @@
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_widget_host_view.h"
 #include "ui/aura/window.h"
+#include "ui/base/layout.h"
 #include "ui/compositor/layer.h"
 #include "ui/compositor/layer_animation_observer.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
@@ -196,8 +197,7 @@ ui::Layer* OverscrollNavigationOverlay::CreateSlideLayer(int offset) {
   if (entry && entry->screenshot().get()) {
     std::vector<gfx::ImagePNGRep> image_reps;
     image_reps.push_back(gfx::ImagePNGRep(entry->screenshot(),
-        ui::GetImageScale(
-            ui::GetScaleFactorForNativeView(window_.get()))));
+        ui::GetScaleFactorForNativeView(window_.get())));
     image = gfx::Image(image_reps);
   }
   if (!layer_delegate_)