Plumbs through support for painting the scrollbarcorner

ui/native_theme/native_theme_base.cc

Index: ui/native_theme/native_theme_base.cc
diff --git a/ui/native_theme/native_theme_base.cc b/ui/native_theme/native_theme_base.cc
index cc0bacbadf26c894938f01601b3bebd20e20eaa2..79cfc151abc24f7680bbe2ca6255f045155b9f76 100644
--- a/ui/native_theme/native_theme_base.cc
+++ b/ui/native_theme/native_theme_base.cc
@@ -216,6 +216,9 @@ void NativeThemeBase::Paint(SkCanvas* canvas,
       // Invoked by views scrollbar code, don't care about for non-win
       // implementations, so no NOTIMPLEMENTED.
       break;
+    case kScrollbarCorner:
+      PaintScrollbarCorner(canvas, state, rect);
+      break;
     case kSliderTrack:
       PaintSliderTrack(canvas, state, rect, extra.slider);
       break;
@@ -488,6 +491,12 @@ void NativeThemeBase::PaintScrollbarThumb(SkCanvas* canvas,
   }
 }
 
+void NativeThemeBase::PaintScrollbarCorner(SkCanvas* canvas,
+                                           State state,
+                                           const gfx::Rect& rect) const {
+  canvas->drawColor(SK_ColorWHITE, SkXfermode::kSrc_Mode);
+}
+
 void NativeThemeBase::PaintCheckbox(SkCanvas* canvas,
                                     State state,
                                     const gfx::Rect& rect,