aura: Unify WindowTreeHost for some platforms

ui/platform_window/platform_window.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 UI_PLATFORM_WINDOW_PLATFORM_WINDOW_H_
 #define UI_PLATFORM_WINDOW_PLATFORM_WINDOW_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/string16.h"
 #include "ui/base/cursor/cursor.h"
 
 namespace gfx {
 class Rect;
 }
 
 namespace ui {
 
 class PlatformImeController;
 class PlatformWindowDelegate;
 
 // Platform window.
 //
 // Each instance of PlatformWindow represents a single window in the
 // underlying platform windowing system (i.e. X11/Win/OSX).
 class PlatformWindow {
  public:
+  static scoped_ptr<PlatformWindow> Create(PlatformWindowDelegate* delegate,

[mfomitchev, 2015/10/08 15:03:27]

IMHO it's better just to do an ifdef in the constructor in  WindowTreeHostImpl.
There's a few problems with adding this method here. E.g. this is currently only
implemented for Windows and Ozone. We need this for other platforms if we are
going to do this. Also the new dependency on Ozone seems unfortunate.

[no sievers, 2015/10/09 00:34:18]

Done. For non-Ozone I left it with the implementation though, since ui_aura
doesn't really need to depend on that (i.e. window_android rather than just
platform_window).

[mfomitchev, 2015/10/09 13:56:54]

Do you mean just in the header files? The Aura module itself would still need to
depend on /ui/platform_window/android, since WTHPlatform would instantiate it on
Android, otherwise we'll get a linking error when building Aura for Android.
Just like Aura depends on /ui/platform_window/win... On this note, I also had to
make Aura depend on //ui/platform_window/android:platform_window_java to make it
run - see https://codereview.chromium.org/1391893003/

Also, if we are going to make that ifdef !defined(USE_OZONE), we need to
implement Create on other platforms (X11, etc). Personally I don't think it's
worth the hassle.

[no sievers, 2015/10/09 20:47:46]

Done.

+                                           const gfx::Rect& bounds);
   virtual ~PlatformWindow() {}
 
   virtual void Show() = 0;
   virtual void Hide() = 0;
   virtual void Close() = 0;
 
   // Sets and gets the bounds of the platform-window. Note that the bounds is in
   // physical pixel coordinates.
   virtual void SetBounds(const gfx::Rect& bounds) = 0;
   virtual gfx::Rect GetBounds() = 0;
@@ skipping 18 matching lines @@
   virtual void ConfineCursorToBounds(const gfx::Rect& bounds) = 0;
 
   // The PlatformImeController is owned by the PlatformWindow, the ownership is
   // not transferred.
   virtual PlatformImeController* GetPlatformImeController() = 0;
 };
 
 }  // namespace ui
 
 #endif  // UI_PLATFORM_WINDOW_PLATFORM_WINDOW_H_