Refactor WindowFinder definition

chrome/browser/ui/views/tabs/window_finder.h

 // Copyright 2014 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 CHROME_BROWSER_UI_VIEWS_TABS_WINDOW_FINDER_H_
 #define CHROME_BROWSER_UI_VIEWS_TABS_WINDOW_FINDER_H_
 
 #include <set>
 
 #include "ui/gfx/native_widget_types.h"
 
 namespace aura {
 class Window;
 }
 
 namespace gfx {
 class Point;
 }
 
 // Class used by the tabstrip to find chrome windows that we can attach tabs
 // to.
 class WindowFinder {

[sky, 2016/10/28 16:54:48]

There is no point in making this a class. A single function suffices. Here is
what I would like to see: no class here. Only the single function:
GetLocalProcessWindowAtPoint().

In window_finder_mus.h there is a function GetLocalProcessWindowAtPointMus()
(again no class, just a function). Make this function have a boolean return
value and an additional param gfx::NativeWindow* value. For the platforms that
support mus, e.g. win, x11... GetLocalProcessWindowAtPoint looks like:

if (GetLocalProcessWindowAtPointMus(...))
  return window;
// existing logic.

Make sense?

[tonikitoo, 2016/10/28 20:05:48]

Yes, it makes sense. patchset 10 implements the idea.

The biggest problem I see now is the unittest
chrome/browser/ui/views/tabs/tab_drag_controller_interactive_uitest.cc , where
WindowFinder is derived and GetLocalProcessWindowAtPoint overriden.

  public:
-  WindowFinder();
-  virtual ~WindowFinder();
+  WindowFinder() {}
+  virtual ~WindowFinder() {}
 
   // Finds the topmost visible chrome window at |screen_point|. This should
   // return nullptr if |screen_point| is in another program's window which
   // occludes the topmost chrome window. Ignores the windows in |ignore|, which
   // contain windows such as the tab being dragged right now.
   virtual gfx::NativeWindow GetLocalProcessWindowAtPoint(
       const gfx::Point& screen_point,
       const std::set<gfx::NativeWindow>& ignore);
 
  private:
+  gfx::NativeWindow GetLocalProcessWindowAtPointImpl(
+      const gfx::Point& screen_point,
+      const std::set<gfx::NativeWindow>& ignore);
+
   DISALLOW_COPY_AND_ASSIGN(WindowFinder);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_TABS_WINDOW_FINDER_H_