Plumbs through support for painting the scrollbarcorner

ui/native_theme/native_theme_base.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/native_theme/native_theme_base.h"
 
 #include <limits>
 
 #include "base/command_line.h"
 #include "base/logging.h"
@@ skipping 198 matching lines @@
       break;
     case kScrollbarHorizontalTrack:
     case kScrollbarVerticalTrack:
       PaintScrollbarTrack(canvas, part, state, extra.scrollbar_track, rect);
       break;
     case kScrollbarHorizontalGripper:
     case kScrollbarVerticalGripper:
       // 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;
     case kSliderThumb:
       PaintSliderThumb(canvas, state, rect, extra.slider);
       break;
     case kTabPanelBackground:
       NOTIMPLEMENTED();
       break;
     case kTextField:
@@ skipping 252 matching lines @@
                    paint);
       DrawVertLine(canvas,
                    midx + inter_grippy_offset,
                    midy - grippy_half_width,
                    midy + grippy_half_width,
                    paint);
     }
   }
 }
 
+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,
                                     const ButtonExtraParams& button) const {
   SkRect skrect = PaintCheckboxRadioCommon(canvas, state, rect,
                                            SkIntToScalar(2));
   if (!skrect.isEmpty()) {
     // Draw the checkmark / dash.
     SkPaint paint;
     paint.setAntiAlias(true);
@@ skipping 616 matching lines @@
   SkScalar min_diff = Clamp((hsv1[1] + hsv2[1]) * 1.2f, 0.28f, 0.5f);
   SkScalar diff = Clamp(fabs(hsv1[2] - hsv2[2]) / 2, min_diff, 0.5f);
 
   if (hsv1[2] + hsv2[2] > 1.0)
     diff = -diff;
 
   return SaturateAndBrighten(hsv2, -0.2f, diff);
 }
 
 }  // namespace ui