Aura overlay scrollbars adjust color for dark backgrounds

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 <memory>
 
 #include "base/command_line.h"
@@ skipping 138 matching lines @@
     case kWindowResizeGripper:
       NOTIMPLEMENTED();
       break;
     default:
       NOTREACHED() << "Unknown theme part: " << part;
       break;
   }
   return gfx::Size();
 }
 
-void NativeThemeBase::PaintStateTransition(SkCanvas* canvas,
-                                           Part part,
-                                           State startState,
-                                           State endState,
-                                           double progress,
-                                           const gfx::Rect& rect) const {
+void NativeThemeBase::PaintStateTransition(
+    SkCanvas* canvas,
+    Part part,
+    State startState,
+    State endState,
+    double progress,
+    const gfx::Rect& rect,
+    ScrollbarOverlayColorTheme theme) const {
   if (rect.IsEmpty())
     return;
 
   // Currently state transition is animation only working for overlay scrollbars
   // on Aura platforms.
   switch (part) {
     case kScrollbarHorizontalThumb:
     case kScrollbarVerticalThumb:
       PaintScrollbarThumbStateTransition(canvas, part, startState, endState,
-                                         progress, rect);
+                                         progress, rect, theme);
       break;
     default:
       NOTREACHED() << "Does not support state transition for this part:"
                    << part;
       break;
   }
   return;
 }
 
 void NativeThemeBase::Paint(SkCanvas* canvas,
@@ skipping 35 matching lines @@
       break;
     case kScrollbarDownArrow:
     case kScrollbarUpArrow:
     case kScrollbarLeftArrow:
     case kScrollbarRightArrow:
       if (scrollbar_button_length_ > 0)
         PaintArrowButton(canvas, rect, part, state);
       break;
     case kScrollbarHorizontalThumb:
     case kScrollbarVerticalThumb:
-      PaintScrollbarThumb(canvas, part, state, rect);
+      PaintScrollbarThumb(canvas, part, state, rect,
+                          extra.scrollbar_thumb.scrollbar_theme);
       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;
@@ skipping 186 matching lines @@
   canvas->drawIRect(skrect, paint);
 
   SkScalar thumb_hsv[3];
   SkColorToHSV(thumb_inactive_color_, thumb_hsv);
 
   paint.setColor(OutlineColor(track_hsv, thumb_hsv));
   DrawBox(canvas, rect, paint);
 }
 
 void NativeThemeBase::PaintScrollbarThumb(SkCanvas* canvas,
-                                           Part part,
-                                           State state,
-                                           const gfx::Rect& rect) const {
+                                          Part part,
+                                          State state,
+                                          const gfx::Rect& rect,
+                                          ScrollbarOverlayColorTheme) const {
   const bool hovered = state == kHovered;
   const int midx = rect.x() + rect.width() / 2;
   const int midy = rect.y() + rect.height() / 2;
   const bool vertical = part == kScrollbarVerticalThumb;
 
   SkScalar thumb[3];
   SkColorToHSV(hovered ? thumb_active_color_ : thumb_inactive_color_, thumb);
 
   SkPaint paint;
   paint.setColor(SaturateAndBrighten(thumb, 0, 0.02f));
@@ skipping 565 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