ui: Make gfx::Size::Scale() mutate the class. Add gfx::ScaleSize() similar to Rect/Point.

chrome/browser/chromeos/status/network_menu_icon.cc

Index: chrome/browser/chromeos/status/network_menu_icon.cc
diff --git a/chrome/browser/chromeos/status/network_menu_icon.cc b/chrome/browser/chromeos/status/network_menu_icon.cc
index d852ac651555f9b8bc6338e30864d72f80e9afec..11f2a26f4b72cb65ebab90dc2aba66d141041f41 100644
--- a/chrome/browser/chromeos/status/network_menu_icon.cc
+++ b/chrome/browser/chromeos/status/network_menu_icon.cc
@@ -184,7 +184,7 @@ class EmptyImageSource: public gfx::ImageSkiaSource {
   virtual gfx::ImageSkiaRep GetImageForScale(
       ui::ScaleFactor scale_factor) OVERRIDE {
     gfx::Size pixel_size = gfx::ToFlooredSize(
-        size_.Scale(ui::GetScaleFactorScale(scale_factor)));
+        gfx::ScaleSize(size_, ui::GetScaleFactorScale(scale_factor)));
     SkBitmap empty_bitmap = GetEmptyBitmap(pixel_size);
     return gfx::ImageSkiaRep(empty_bitmap, scale_factor);
   }