Refactors std::vector<Display> out of ScreenMus

mash/wm/test/wm_test_screen.h

Index: mash/wm/test/wm_test_screen.h
diff --git a/mash/wm/test/wm_test_screen.h b/mash/wm/test/wm_test_screen.h
new file mode 100644
index 0000000000000000000000000000000000000000..2849cd4d1f6684b7e9d430454d9533937d732eb1
--- /dev/null
+++ b/mash/wm/test/wm_test_screen.h
@@ -0,0 +1,48 @@
+// Copyright 2016 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 MASH_WM_WM_TEST_SCREEN_H_
+#define MASH_WM_WM_TEST_SCREEN_H_
+
+#include "ui/display/screen.h"
+#include "ui/views/mus/display_list.h"
+
+namespace mash {
+namespace wm {
+
+// Screen implementation used by tests for the windowmanager. Does not talk
+// to mus. Tests must keep the list of Displays in sync manually.
+class WmTestScreen : public display::Screen {
+ public:
+  WmTestScreen();
+  ~WmTestScreen() override;
+
+  const views::DisplayList& display_list() const { return display_list_; }
+  views::DisplayList* display_list() { return &display_list_; }
+
+ private:
+  // display::Screen:
+  gfx::Point GetCursorScreenPoint() override;
+  bool IsWindowUnderCursor(gfx::NativeWindow window) override;
+  gfx::NativeWindow GetWindowAtScreenPoint(const gfx::Point& point) override;
+  display::Display GetPrimaryDisplay() const override;
+  display::Display GetDisplayNearestWindow(gfx::NativeView view) const override;
+  display::Display GetDisplayNearestPoint(
+      const gfx::Point& point) const override;
+  int GetNumDisplays() const override;
+  std::vector<display::Display> GetAllDisplays() const override;
+  display::Display GetDisplayMatching(
+      const gfx::Rect& match_rect) const override;
+  void AddObserver(display::DisplayObserver* observer) override;
+  void RemoveObserver(display::DisplayObserver* observer) override;
+
+  views::DisplayList display_list_;
+
+  DISALLOW_COPY_AND_ASSIGN(WmTestScreen);
+};
+
+}  // namespace wm
+}  // namespace mash
+
+#endif  // MASH_WM_WM_TEST_SCREEN_H_