Restore aura support from Mojo repo.

mandoline/ui/aura/screen_mojo.h

Index: mandoline/ui/aura/screen_mojo.h
diff --git a/mandoline/ui/aura/screen_mojo.h b/mandoline/ui/aura/screen_mojo.h
new file mode 100644
index 0000000000000000000000000000000000000000..964c21adf9ece690ba5afccef07810e55c847887
--- /dev/null
+++ b/mandoline/ui/aura/screen_mojo.h
@@ -0,0 +1,49 @@
+// Copyright 2015 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 MANDOLINE_UI_AURA_SCREEN_MOJO_H_
+#define MANDOLINE_UI_AURA_SCREEN_MOJO_H_
+
+#include "base/macros.h"
+#include "ui/gfx/display.h"
+#include "ui/gfx/screen.h"
+
+namespace gfx {
+class Rect;
+class Transform;
+}
+
+namespace mandoline {
+
+// A minimal implementation of gfx::Screen for mojo.
+class ScreenMojo : public gfx::Screen {
+ public:
+  static ScreenMojo* Create();
+  ~ScreenMojo() override;
+
+ protected:
+  // gfx::Screen overrides:
+  gfx::Point GetCursorScreenPoint() override;
+  gfx::NativeWindow GetWindowUnderCursor() override;
+  gfx::NativeWindow GetWindowAtScreenPoint(const gfx::Point& point) override;
+  int GetNumDisplays() const override;
+  std::vector<gfx::Display> GetAllDisplays() const override;
+  gfx::Display GetDisplayNearestWindow(gfx::NativeView view) const override;
+  gfx::Display GetDisplayNearestPoint(const gfx::Point& point) const override;
+  gfx::Display GetDisplayMatching(const gfx::Rect& match_rect) const override;
+  gfx::Display GetPrimaryDisplay() const override;
+  void AddObserver(gfx::DisplayObserver* observer) override;
+  void RemoveObserver(gfx::DisplayObserver* observer) override;
+
+ private:
+  explicit ScreenMojo(const gfx::Rect& screen_bounds);
+
+  gfx::Display display_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScreenMojo);
+};
+
+}  // namespace mandoline
+
+#endif  // MANDOLINE_UI_AURA_SCREEN_MOJO_H_