Gtk3: Render a GtkHeaderBar as the background of the tab strip

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 154 matching lines @@
     return;
 
   canvas->save();
   canvas->clipRect(gfx::RectToSkRect(rect));
 
   switch (part) {
     // Please keep these in the order of NativeTheme::Part.
     case kCheckbox:
       PaintCheckbox(canvas, state, rect, extra.button);
       break;
+    case kFrameTopArea:
+      PaintFrameTopArea(canvas, state, rect, extra.frame_top_area);
+      break;
     case kInnerSpinButton:
       PaintInnerSpinButton(canvas, state, rect, extra.inner_spin);
       break;
     case kMenuList:
       PaintMenuList(canvas, state, rect, extra.menu_list);
       break;
     case kMenuPopupBackground:
       PaintMenuPopupBackground(canvas, rect.size(), extra.menu_background);
       break;
     case kMenuItemBackground:
@@ skipping 706 matching lines @@
   progress_paint.setStyle(SkPaint::kFill_Style);
   canvas->drawRect(gfx::RectToSkRect(progress_rect), progress_paint);
 
   // Draw the border.
   gfx::RectF border_rect(rect);
   border_rect.Inset(stroke_width / 2.0f, stroke_width / 2.0f);
   stroke_paint.setColor(kProgressBorderColor);
   canvas->drawRect(gfx::RectFToSkRect(border_rect), stroke_paint);
 }
 
+void NativeThemeBase::PaintFrameTopArea(
+    SkCanvas* canvas,
+    State state,
+    const gfx::Rect& rect,
+    const FrameTopAreaExtraParams& frame_top_area) const {
+  SkPaint paint;
+  paint.setColor(frame_top_area.default_background_color);
+  canvas->drawRect(gfx::RectToSkRect(rect), paint);
+}
+
 void NativeThemeBase::AdjustCheckboxRadioRectForPadding(SkRect* rect) const {
   // By default we only take 1px from right and bottom for the drop shadow.
   rect->iset(rect->x(), rect->y(), rect->right() - 1, rect->bottom() - 1);
 }
 
 SkColor NativeThemeBase::SaturateAndBrighten(SkScalar* hsv,
                                              SkScalar saturate_amount,
                                              SkScalar brighten_amount) const {
   SkScalar color[3];
   color[0] = hsv[0];
@@ skipping 81 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