Dark Mode: split out TestNativeTheme as a separate class/target

There was a handy dandy testing version of NativeTheme in
view_unittest.cc that I'd like to reuse in upcoming unit tests for WebUI
Dark Mode support (https://crrev.com/c/1354685).

BUG=883049
R=sky@chromium.org

Change-Id: Ie39f6c42f5069450ec9933b1b83d4cb615ab713d
Reviewed-on: https://chromium-review.googlesource.com/c/1357607
Commit-Queue: Dan Beam <dbeam@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#613233}

ui/native_theme/BUILD.gn

@@ -37,11 +37,14 @@ jumbo_component("native_theme") {
 
   defines = [ "NATIVE_THEME_IMPLEMENTATION" ]
 
+  public_deps = [
+    "//skia",
+  ]
+
   deps = [
     "//base",
     "//base/third_party/dynamic_annotations",
     "//cc/paint",
-    "//skia",
     "//ui/base",
     "//ui/display",
     "//ui/gfx",
@@ -81,6 +84,20 @@ if (is_win) {
   }
 }
 
+jumbo_source_set("test_support") {
+  testonly = true
+
+  deps = [
+    ":native_theme",
+    "//base",
+  ]
+
+  sources = [
+    "test_native_theme.cc",
+    "test_native_theme.h",
+  ]
+}
+
 test("native_theme_unittests") {
   sources = []
 

ui/native_theme/test_native_theme.cc

@@ -0,0 +1,48 @@
+// Copyright 2018 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/test_native_theme.h"
+
+namespace ui {
+
+TestNativeTheme::TestNativeTheme() {}
+TestNativeTheme::~TestNativeTheme() {}
+
+SkColor TestNativeTheme::GetSystemColor(ColorId color_id) const {
+  return SK_ColorRED;
+}
+
+gfx::Size TestNativeTheme::GetPartSize(Part part,
+                                       State state,
+                                       const ExtraParams& extra) const {
+  return gfx::Size();
+}
+
+void TestNativeTheme::Paint(cc::PaintCanvas* canvas,
+                            Part part,
+                            State state,
+                            const gfx::Rect& rect,
+                            const ExtraParams& extra) const {}
+
+bool TestNativeTheme::SupportsNinePatch(Part part) const {
+  return false;
+}
+
+gfx::Size TestNativeTheme::GetNinePatchCanvasSize(Part part) const {
+  return gfx::Size();
+}
+
+gfx::Rect TestNativeTheme::GetNinePatchAperture(Part part) const {
+  return gfx::Rect();
+}
+
+bool TestNativeTheme::UsesHighContrastColors() const {
+  return false;
+}
+
+bool TestNativeTheme::SystemDarkModeEnabled() const {
+  return dark_mode_;
+}
+
+}  // namespace ui

ui/native_theme/test_native_theme.h

@@ -0,0 +1,44 @@
+// Copyright 2018 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.
+
+#ifndef UI_NATIVE_THEME_TEST_NATIVE_THEME_H_
+#define UI_NATIVE_THEME_TEST_NATIVE_THEME_H_
+
+#include "base/macros.h"
+#include "ui/native_theme/native_theme.h"
+
+namespace ui {
+
+class TestNativeTheme : public NativeTheme {
+ public:
+  TestNativeTheme();
+  ~TestNativeTheme() override;
+
+  // NativeTheme:
+  SkColor GetSystemColor(ColorId color_id) const override;
+  gfx::Size GetPartSize(Part part,
+                        State state,
+                        const ExtraParams& extra) const override;
+  void Paint(cc::PaintCanvas* canvas,
+             Part part,
+             State state,
+             const gfx::Rect& rect,
+             const ExtraParams& extra) const override;
+  bool SupportsNinePatch(Part part) const override;
+  gfx::Size GetNinePatchCanvasSize(Part part) const override;
+  gfx::Rect GetNinePatchAperture(Part part) const override;
+  bool UsesHighContrastColors() const override;
+  bool SystemDarkModeEnabled() const override;
+
+  void SetDarkMode(bool dark_mode) { dark_mode_ = dark_mode; }
+
+ private:
+  bool dark_mode_ = false;
+
+  DISALLOW_COPY_AND_ASSIGN(TestNativeTheme);
+};
+
+}  // namespace ui
+
+#endif  // UI_NATIVE_THEME_TEST_NATIVE_THEME_H_

ui/views/BUILD.gn

@@ -1073,6 +1073,7 @@ source_set("views_unittests_sources") {
     "//ui/gfx/geometry",
     "//ui/gl:test_support",
     "//ui/native_theme",
+    "//ui/native_theme:test_support",
     "//ui/resources",
     "//ui/resources:ui_test_pak",
     "//ui/strings",

ui/views/view_unittest.cc

@@ -41,6 +41,7 @@
 #include "ui/gfx/path.h"
 #include "ui/gfx/transform.h"
 #include "ui/native_theme/native_theme.h"
+#include "ui/native_theme/test_native_theme.h"
 #include "ui/strings/grit/ui_strings.h"
 #include "ui/views/background.h"
 #include "ui/views/controls/native/native_view_host.h"
@@ -4787,41 +4788,6 @@ class ViewThatAddsViewInOnNativeThemeChanged : public View {
   DISALLOW_COPY_AND_ASSIGN(ViewThatAddsViewInOnNativeThemeChanged);
 };
 
-// See comment above test for details.
-class TestNativeTheme : public ui::NativeTheme {
- public:
-  TestNativeTheme() {}
-  ~TestNativeTheme() override {}
-
-  // ui::NativeTheme:
-  SkColor GetSystemColor(ColorId color_id) const override {
-    return SK_ColorRED;
-  }
-  gfx::Size GetPartSize(Part part,
-                        State state,
-                        const ExtraParams& extra) const override {
-    return gfx::Size();
-  }
-  void Paint(cc::PaintCanvas* canvas,
-             Part part,
-             State state,
-             const gfx::Rect& rect,
-             const ExtraParams& extra) const override {}
-
-  bool SupportsNinePatch(Part part) const override { return false; }
-  gfx::Size GetNinePatchCanvasSize(Part part) const override {
-    return gfx::Size();
-  }
-  gfx::Rect GetNinePatchAperture(Part part) const override {
-    return gfx::Rect();
-  }
-  bool UsesHighContrastColors() const override { return false; }
-  bool SystemDarkModeEnabled() const override { return false; }
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(TestNativeTheme);
-};
-
 // Creates and adds a new child view to |parent| that has a layer.
 void AddViewWithChildLayer(View* parent) {
   View* child = new View;
@@ -4838,7 +4804,7 @@ void AddViewWithChildLayer(View* parent) {
 // before the layer hierarchy was updated. OnNativeThemeChanged() should be
 // called after the layer hierarchy matches the view hierarchy.
 TEST_F(ViewTest, CrashOnAddFromFromOnNativeThemeChanged) {
-  TestNativeTheme theme;
+  ui::TestNativeTheme theme;
   WidgetWithCustomTheme widget(&theme);
   Widget::InitParams params = CreateParams(Widget::InitParams::TYPE_POPUP);
   params.ownership = views::Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;