Aura overlay scrollbars adjust color for dark backgrounds

content/child/webthemeengine_impl_default.cc

 // Copyright 2014 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 "content/child/webthemeengine_impl_default.h"
 
 #include "build/build_config.h"
 #include "skia/ext/platform_canvas.h"
 #include "third_party/WebKit/public/platform/WebRect.h"
 #include "third_party/WebKit/public/platform/WebSize.h"
-#include "ui/native_theme/native_theme.h"
 
 using blink::WebCanvas;
 using blink::WebColor;
 using blink::WebRect;
 using blink::WebThemeEngine;
 
 namespace content {
 namespace {
 
 #if defined(OS_WIN)
@@ skipping 148 matching lines @@
           extra_params->progressBar.determinate;
       native_theme_extra_params->progress_bar.value_rect_x =
           extra_params->progressBar.valueRectX;
       native_theme_extra_params->progress_bar.value_rect_y =
           extra_params->progressBar.valueRectY;
       native_theme_extra_params->progress_bar.value_rect_width =
           extra_params->progressBar.valueRectWidth;
       native_theme_extra_params->progress_bar.value_rect_height =
           extra_params->progressBar.valueRectHeight;
       break;
+    case WebThemeEngine::PartScrollbarHorizontalThumb:
+    case WebThemeEngine::PartScrollbarVerticalThumb:
+      if (extra_params) {
+        native_theme_extra_params->scrollbar_theme =

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

These should be |native_theme_extra_params->scrollbar_thumb.scrollbar_theme|.
See my comment in native_theme.h.

+            static_cast<ui::NativeTheme::ScrollbarOverlayColorTheme>(
+                extra_params->scrollbarTheme);
+      } else {

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

The other cases here assume extra_params is always given, seems we can assume
that too.

+        native_theme_extra_params->scrollbar_theme = ui::NativeTheme::
+            ScrollbarOverlayColorTheme::ScrollbarOverlayColorThemeDefault;
+      }
+      break;
     default:
       break;  // Parts that have no extra params get here.
   }
 }
 
 blink::WebSize WebThemeEngineImpl::getSize(WebThemeEngine::Part part) {
   ui::NativeTheme::ExtraParams extra;
   ui::NativeTheme::Part native_theme_part = NativeThemePart(part);
 #if defined(OS_WIN)
   switch (native_theme_part) {
@@ skipping 24 matching lines @@
     const blink::WebRect& rect,
     const WebThemeEngine::ExtraParams* extra_params) {
   ui::NativeTheme::ExtraParams native_theme_extra_params;
   GetNativeThemeExtraParams(
       part, state, extra_params, &native_theme_extra_params);
   ui::NativeTheme::GetInstanceForWeb()->Paint(
       canvas, NativeThemePart(part), NativeThemeState(state), gfx::Rect(rect),
       native_theme_extra_params);
 }
 
-void WebThemeEngineImpl::paintStateTransition(blink::WebCanvas* canvas,
-                                              WebThemeEngine::Part part,
-                                              WebThemeEngine::State startState,
-                                              WebThemeEngine::State endState,
-                                              double progress,
-                                              const blink::WebRect& rect) {
+void WebThemeEngineImpl::paintStateTransition(
+    blink::WebCanvas* canvas,
+    WebThemeEngine::Part part,
+    WebThemeEngine::State startState,
+    WebThemeEngine::State endState,
+    double progress,
+    const blink::WebRect& rect,
+    ui::NativeTheme::ScrollbarOverlayColorTheme theme) {
   ui::NativeTheme::GetInstanceForWeb()->PaintStateTransition(
       canvas, NativeThemePart(part), NativeThemeState(startState),
-      NativeThemeState(endState), progress, gfx::Rect(rect));
+      NativeThemeState(endState), progress, gfx::Rect(rect), theme);
 }
 
 #if defined(OS_WIN)
 // static
 void WebThemeEngineImpl::cacheScrollBarMetrics(
     int32_t vertical_scroll_bar_width,
     int32_t horizontal_scroll_bar_height,
     int32_t vertical_arrow_bitmap_height,
     int32_t horizontal_arrow_bitmap_width) {
   g_vertical_scroll_bar_width = vertical_scroll_bar_width;
   g_horizontal_scroll_bar_height = horizontal_scroll_bar_height;
   g_vertical_arrow_bitmap_height = vertical_arrow_bitmap_height;
   g_horizontal_arrow_bitmap_width = horizontal_arrow_bitmap_width;
 }
 #endif
 
 }  // namespace content