Ensure Surface size always matches window size on swap

ui/views/win/hwnd_message_handler.cc

 // 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.
 
 #include "ui/views/win/hwnd_message_handler.h"
 
 #include <dwmapi.h>
 #include <oleacc.h>
 #include <shellapi.h>
 #include <wtsapi32.h>
@@ skipping 2268 matching lines @@
             FROM_HERE,
             base::Bind(&HWNDMessageHandler::StopIgnoringPosChanges,
                        weak_factory_.GetWeakPtr()));
       }
       last_monitor_ = monitor;
       last_monitor_rect_ = monitor_rect;
       last_work_area_ = work_area;
     }
   }
 
-  if (DidClientAreaSizeChange(window_pos))
+  RECT window_rect;
+  gfx::Size old_size;
+  if (GetWindowRect(hwnd(), &window_rect))
+    old_size = gfx::Rect(window_rect).size();
+  gfx::Size new_size = gfx::Size(window_pos->cx, window_pos->cy);
+  if ((old_size != new_size && !(window_pos->flags & SWP_NOSIZE)) ||
+      window_pos->flags & SWP_FRAMECHANGED) {
     delegate_->HandleWindowSizeChanging();
+  }
 
   if (ScopedFullscreenVisibility::IsHiddenForFullscreen(hwnd())) {
     // Prevent the window from being made visible if we've been asked to do so.
     // See comment in header as to why we might want this.
     window_pos->flags &= ~SWP_SHOWWINDOW;
   }
 
   if (window_pos->flags & SWP_SHOWWINDOW)
     delegate_->HandleVisibilityChanging(true);
   else if (window_pos->flags & SWP_HIDEWINDOW)
@@ skipping 196 matching lines @@
     SetWindowPos(hwnd(), NULL, 0, 0, 0, 0, flags | SWP_HIDEWINDOW);
     SetWindowPos(hwnd(), NULL, 0, 0, 0, 0, flags | SWP_SHOWWINDOW);
   }
   // WM_DWMCOMPOSITIONCHANGED is only sent to top level windows, however we want
   // to notify our children too, since we can have MDI child windows who need to
   // update their appearance.
   EnumChildWindows(hwnd(), &SendDwmCompositionChanged, NULL);
 }
 
 }  // namespace views