Add display::GetDisplayNearestView

ui/display/screen.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_SCREEN_H_
 #define UI_DISPLAY_SCREEN_H_
 
 #include <vector>
 
 #include "base/macros.h"
@@ skipping 40 matching lines @@
   // Mirrored displays are excluded; this method is intended to return the
   // number of distinct, usable displays.
   virtual int GetNumDisplays() const = 0;
 
   // Returns the list of displays that are currently available.
   virtual const std::vector<Display>& GetAllDisplays() const = 0;
 
   // Returns the display nearest the specified window.
   // If the window is NULL or the window is not rooted to a display this will
   // return the primary display.
+  // TODO(jinsukkim): Fix the parameter type to |gfx::NativeWindow|.

[tapted, 2017/03/06 00:01:49]

I think the CL is simple enough that we should pursue this now. And we need to
force a bit more "fallout" before we know if this approach is going to work - as
it is, nothing is calling WindowForView(). So it is dead code, and we try not to
add dead code to Chrome unless we are sure it will be used.

[Jinsuk Kim, 2017/03/06 06:06:19]

No problem. Will add it when it gets actually put to use. Removed.

   virtual Display GetDisplayNearestWindow(gfx::NativeView view) const = 0;
 
+  // Returns the display nearest the specified view. It may still use the window
+  // that contains the view (i.e. if a window is spread over two displays,
+  // the location of the view within that window won't influence the result).
+  virtual Display GetDisplayNearestView(gfx::NativeView view) const;
+
   // Returns the display nearest the specified point. |point| should be in DIPs.
   virtual Display GetDisplayNearestPoint(const gfx::Point& point) const = 0;
 
   // Returns the display that most closely intersects the provided bounds.
   virtual Display GetDisplayMatching(const gfx::Rect& match_rect) const = 0;
 
   // Returns the primary display.
   virtual Display GetPrimaryDisplay() const = 0;
 
   // Adds/Removes display observers.
@@ skipping 11 matching lines @@
   // If |view| is null, the primary display is used as the context.
   virtual gfx::Rect DIPToScreenRectInWindow(gfx::NativeView view,
                                             const gfx::Rect& dip_rect) const;
 
   // Returns true if the display with |display_id| is found and returns that
   // display in |display|. Otherwise returns false and |display| remains
   // untouched.
   bool GetDisplayWithDisplayId(int64_t display_id, Display* display) const;
 
  private:
+  static gfx::NativeWindow WindowForView(gfx::NativeView view);
+
   DISALLOW_COPY_AND_ASSIGN(Screen);
 };
 
 Screen* CreateNativeScreen();
 
 }  // namespace display
 
 #endif  // UI_DISPLAY_SCREEN_H_