Restore NativeWidgetWin::OnSetIcon to eliminate classic theme titlebar flickering.

ui/views/widget/native_widget_win.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_VIEWS_WIDGET_NATIVE_WIDGET_WIN_H_
 #define UI_VIEWS_WIDGET_NATIVE_WIDGET_WIN_H_
 
 #include <atlbase.h>
 #include <atlapp.h>
 #include <atlcrack.h>
@@ skipping 343 matching lines @@
     MSG_WM_MOVE(OnMove)
     MSG_WM_MOVING(OnMoving)
     MSG_WM_NCACTIVATE(OnNCActivate)
     MSG_WM_NCCALCSIZE(OnNCCalcSize)
     MSG_WM_NCHITTEST(OnNCHitTest)
     MSG_WM_NCPAINT(OnNCPaint)
     MSG_WM_NOTIFY(OnNotify)
     MSG_WM_PAINT(OnPaint)
     MSG_WM_POWERBROADCAST(OnPowerBroadcast)
     MSG_WM_SETFOCUS(OnSetFocus)
+    MSG_WM_SETICON(OnSetIcon)
     MSG_WM_SETTEXT(OnSetText)
     MSG_WM_SETTINGCHANGE(OnSettingChange)
     MSG_WM_SIZE(OnSize)
     MSG_WM_SYSCOMMAND(OnSysCommand)
     MSG_WM_THEMECHANGED(OnThemeChanged)
     MSG_WM_VSCROLL(OnVScroll)
     MSG_WM_WINDOWPOSCHANGING(OnWindowPosChanging)
     MSG_WM_WINDOWPOSCHANGED(OnWindowPosChanged)
   END_MSG_MAP()
 
@@ skipping 46 matching lines @@
   virtual LRESULT OnNCUAHDrawCaption(UINT msg,
                                      WPARAM w_param,
                                      LPARAM l_param);
   virtual LRESULT OnNCUAHDrawFrame(UINT msg, WPARAM w_param, LPARAM l_param);
   virtual LRESULT OnNotify(int w_param, NMHDR* l_param);
   virtual void OnPaint(HDC dc);
   virtual LRESULT OnPowerBroadcast(DWORD power_event, DWORD data);
   virtual LRESULT OnReflectedMessage(UINT msg, WPARAM w_param, LPARAM l_param);
   virtual LRESULT OnSetCursor(UINT message, WPARAM w_param, LPARAM l_param);
   virtual void OnSetFocus(HWND old_focused_window);
+  virtual LRESULT OnSetIcon(UINT size_type, HICON new_icon);
   virtual LRESULT OnSetText(const wchar_t* text);
   virtual void OnSettingChange(UINT flags, const wchar_t* section);
   virtual void OnSize(UINT param, const CSize& size);
   virtual void OnSysCommand(UINT notification_code, CPoint click);
   virtual void OnThemeChanged();
   virtual LRESULT OnTouchEvent(UINT message, WPARAM w_param, LPARAM l_param);
   virtual void OnVScroll(int scroll_type, short position, HWND scrollbar);
   virtual void OnWindowPosChanging(WINDOWPOS* window_pos);
   virtual void OnWindowPosChanged(WINDOWPOS* window_pos);
 
@@ skipping 239 matching lines @@
 
   // The set of touch devices currently down.
   TouchIDs touch_ids_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeWidgetWin);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_NATIVE_WIDGET_WIN_H_