cc: Create a cc::ScrollbarThemePainter and an adapter class in compositor bindings.

cc/test/fake_scrollbar_theme_painter.cc

+// Copyright 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 "cc/test/fake_scrollbar_theme_painter.h"
+#include "third_party/skia/include/core/SkCanvas.h"
+#include "ui/gfx/rect.h"
+
+namespace cc {
+
+void FakeScrollbarThemePainter::PaintScrollbarBackground(
+    SkCanvas* canvas, const gfx::Rect& rect) {
+  Paint(canvas, rect);
+}
+
+void FakeScrollbarThemePainter::PaintTrackBackground(
+    SkCanvas* canvas, const gfx::Rect& rect) {
+  Paint(canvas, rect);
+}
+
+void FakeScrollbarThemePainter::PaintBackTrackPart(
+    SkCanvas* canvas, const gfx::Rect& rect) {
+  Paint(canvas, rect);
+}
+
+void FakeScrollbarThemePainter::PaintForwardTrackPart(
+    SkCanvas* canvas, const gfx::Rect& rect) {
+  Paint(canvas, rect);
+}
+
+void FakeScrollbarThemePainter::PaintBackButtonStart(
+    SkCanvas* canvas, const gfx::Rect& rect) {
+  Paint(canvas, rect);
+}
+
+void FakeScrollbarThemePainter::PaintBackButtonEnd(
+    SkCanvas* canvas, const gfx::Rect& rect) {
+  Paint(canvas, rect);
+}
+
+void FakeScrollbarThemePainter::PaintForwardButtonStart(
+    SkCanvas* canvas, const gfx::Rect& rect) {
+  Paint(canvas, rect);
+}
+
+void FakeScrollbarThemePainter::PaintForwardButtonEnd(
+    SkCanvas* canvas, const gfx::Rect& rect) {
+  Paint(canvas, rect);
+}
+
+void FakeScrollbarThemePainter::PaintTickmarks(
+    SkCanvas* canvas, const gfx::Rect& rect) {
+  Paint(canvas, rect);
+}
+
+void FakeScrollbarThemePainter::PaintThumb(
+    SkCanvas* canvas, const gfx::Rect& rect) {
+  Paint(canvas, rect);
+}
+
+void FakeScrollbarThemePainter::Paint(SkCanvas* canvas, gfx::Rect rect) {
+  if (!paint_)
+    return;
+  // Fill the scrollbar with a different color each time.
+  ++fill_color_;
+  canvas->clear(SK_ColorBLACK | fill_color_);
+}
+
+}  // namespace cc