MacViews: Provide CreateNativeWidget and a stub NativeThemeMac in NativeWidgetMac

This is to get a baseline in tests so we can track coverage of future
CLs.

With this CL, 182 views_unittests pass (up from 125), but that's
incidental.

BUG=378134

Review URL: https://codereview.chromium.org/328103002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@276556 0039d316-1c4b-4281-b951-d872f2087c98

ui/native_theme/native_theme_mac.h

@@ -5,12 +5,14 @@
 #ifndef UI_NATIVE_THEME_NATIVE_THEME_MAC_H_
 #define UI_NATIVE_THEME_NATIVE_THEME_MAC_H_
 
-#include "ui/native_theme/native_theme_base.h"
+#include "ui/native_theme/fallback_theme.h"
+#include "ui/native_theme/native_theme_export.h"
 
 namespace ui {
 
 // Mac implementation of native theme support.
-class NativeThemeMac : public NativeThemeBase {
+// TODO(tapted): This should not use FallbackTheme. http://crbug.com/379086.
+class NativeThemeMac : public FallbackTheme {
  public:
   static NativeThemeMac* instance();
 

ui/native_theme/native_theme_mac.mm

@@ -36,7 +36,8 @@ SkColor NativeThemeMac::GetSystemColor(ColorId color_id) const {
     case kColorId_DialogBackground:
       return kDialogBackgroundColor;
     default:
-      NOTREACHED() << "Invalid color_id: " << color_id;
+      NOTIMPLEMENTED() << " Invalid color_id: " << color_id;
+      return FallbackTheme::GetSystemColor(color_id);
   }
 
   return kInvalidColorIdColor;

ui/views/widget/native_widget_mac.mm

@@ -7,6 +7,7 @@
 #include <Cocoa/Cocoa.h>
 
 #include "ui/gfx/font_list.h"
+#include "ui/native_theme/native_theme.h"
 
 namespace views {
 
@@ -347,8 +348,7 @@ void NativeWidgetMac::SetVisibilityChangedAnimationsEnabled(bool value) {
 }
 
 ui::NativeTheme* NativeWidgetMac::GetNativeTheme() const {
-  NOTIMPLEMENTED();
-  return NULL;
+  return ui::NativeTheme::instance();
 }
 
 void NativeWidgetMac::OnRootViewLayout() const {
@@ -376,8 +376,7 @@ namespace internal {
 // static
 NativeWidgetPrivate* NativeWidgetPrivate::CreateNativeWidget(
     internal::NativeWidgetDelegate* delegate) {
-  NOTIMPLEMENTED();
-  return NULL;
+  return new NativeWidgetMac(delegate);
 }
 
 // static