Aura overlay scrollbars adjust color for dark backgrounds

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 331ceb46be0a5bfe58551fccd79bd72ee21cbf3f..995910000caaba3b7bd39fe3b21e8e1480b41e6e 100644
--- a/ui/native_theme/native_theme_base.cc
+++ b/ui/native_theme/native_theme_base.cc
@@ -156,12 +156,14 @@ gfx::Size NativeThemeBase::GetPartSize(Part part,
   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;
 
@@ -171,7 +173,7 @@ void NativeThemeBase::PaintStateTransition(SkCanvas* canvas,
     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:"
@@ -227,7 +229,7 @@ void NativeThemeBase::Paint(SkCanvas* canvas,
       break;
     case kScrollbarHorizontalThumb:
     case kScrollbarVerticalThumb:
-      PaintScrollbarThumb(canvas, part, state, rect);
+      PaintScrollbarThumb(canvas, part, state, rect, extra.scrollbar_theme);
       break;
     case kScrollbarHorizontalTrack:
     case kScrollbarVerticalTrack:
@@ -433,10 +435,12 @@ void NativeThemeBase::PaintScrollbarTrack(SkCanvas* canvas,
   DrawBox(canvas, rect, paint);
 }
 
-void NativeThemeBase::PaintScrollbarThumb(SkCanvas* canvas,
-                                           Part part,
-                                           State state,
-                                           const gfx::Rect& rect) const {
+void NativeThemeBase::PaintScrollbarThumb(
+    SkCanvas* canvas,
+    Part part,
+    State state,
+    const gfx::Rect& rect,
+    ScrollbarOverlayColorTheme theme) const {

[bokan, 2016/10/21 16:57:14]

Make the param unnamed since |theme| is unused here.

   const bool hovered = state == kHovered;
   const int midx = rect.x() + rect.width() / 2;
   const int midy = rect.y() + rect.height() / 2;