Move kInvalidDisplayID to display_constants.h.

ui/display/display.h

 // Copyright (c) 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.
 
 #ifndef UI_DISPLAY_DISPLAY_H_
 #define UI_DISPLAY_DISPLAY_H_
 
 #include <stdint.h>
 
 #include "base/compiler_specific.h"
 #include "ui/display/display_export.h"
+#include "ui/display/types/display_constants.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/icc_profile.h"
 
 #if !defined(OS_IOS)
 #include "mojo/public/cpp/bindings/struct_traits.h"  // nogncheck
 #endif
 
 namespace display {
 
 #if !defined(OS_IOS)
@@ skipping 36 matching lines @@
     ROTATION_SOURCE_UNKNOWN,
   };
 
   // Touch support for the display.
   enum TouchSupport {
     TOUCH_SUPPORT_UNKNOWN,
     TOUCH_SUPPORT_AVAILABLE,
     TOUCH_SUPPORT_UNAVAILABLE,
   };
 
-  enum : int64_t { kInvalidDisplayID = -1 };
+  // Use display::kInvalidDisplayID from display_constants.h in new code.
+  enum : int64_t { kInvalidDisplayID = display::kInvalidDisplayID };

[sadrul, 2016/11/21 17:31:17]

Get rid of it?

[kylechar, 2016/11/21 17:51:18]

It's still used everywhere that isn't src/ui/* but I'll switch that next and
remove it. Added a TODO.

 
   // Creates a display with kInvalidDisplayID as default.
   Display();
   explicit Display(int64_t id);
   Display(int64_t id, const gfx::Rect& bounds);
   Display(const Display& other);
   ~Display();
 
   // Returns the forced device scale factor, which is given by
   // "--force-device-scale-factor".
@@ skipping 127 matching lines @@
 
 #if !defined(OS_IOS)
   friend struct mojo::StructTraits<display::mojom::DisplayDataView,
                                    display::Display>;
 #endif
 };
 
 }  // namespace display
 
 #endif  // UI_DISPLAY_DISPLAY_H_