Fixes bug in paint scrollbar corner (again)

ui/native_theme/native_theme_aura.cc

Index: ui/native_theme/native_theme_aura.cc
diff --git a/ui/native_theme/native_theme_aura.cc b/ui/native_theme/native_theme_aura.cc
index 91e5ec1ebde68f14e0923c4930aa3c77f0a1c88b..bcec3fa78cf9030a11205badf6c455ecba318f69 100644
--- a/ui/native_theme/native_theme_aura.cc
+++ b/ui/native_theme/native_theme_aura.cc
@@ -15,6 +15,7 @@
 #include "ui/gfx/rect.h"
 #include "ui/gfx/size.h"
 #include "ui/gfx/skbitmap_operations.h"
+#include "ui/gfx/skia_util.h"
 #include "ui/native_theme/common_theme.h"
 
 using gfx::NineImagePainter;
@@ -166,7 +167,11 @@ void NativeThemeAura::PaintScrollbarThumb(SkCanvas* sk_canvas,
 void NativeThemeAura::PaintScrollbarCorner(SkCanvas* canvas,
                                            State state,
                                            const gfx::Rect& rect) const {
-  canvas->drawColor(SkColorSetRGB(0xF1, 0xF1, 0xF1), SkXfermode::kSrc_Mode);
+  SkPaint paint;
+  paint.setColor(SkColorSetRGB(0xF1, 0xF1, 0xF1));
+  paint.setStyle(SkPaint::kFill_Style);
+  paint.setXfermodeMode(SkXfermode::kSrc_Mode);
+  canvas->drawIRect(RectToSkIRect(rect), paint);
 }
 
 NineImagePainter* NativeThemeAura::GetOrCreatePainter(