Reduce the fullscreen window height by 1px on activation loss.

ui/views/win/hwnd_message_handler.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_WIN_HWND_MESSAGE_HANDLER_H_
 #define UI_VIEWS_WIN_HWND_MESSAGE_HANDLER_H_
 
 #include <windows.h>
 #include <stddef.h>
 
@@ skipping 188 matching lines @@
 
   void set_use_system_default_icon(bool use_system_default_icon) {
     use_system_default_icon_ = use_system_default_icon;
   }
 
   void SetFullscreen(bool fullscreen);
 
   // Updates the window style to reflect whether it can be resized or maximized.
   void SizeConstraintsChanged();
 
+  // Setter getter combination for a background fullscreen window, i.e a
+  // fullscreen window which lost activation.
+  void set_background_fullscreen_hack(bool set_background_fullscreen) {
+    background_fullscreen_hack_ = set_background_fullscreen;
+  }
+
+  bool background_fullscreen_hack() const {
+    return background_fullscreen_hack_;
+  }
+
  private:
   typedef std::set<DWORD> TouchIDs;
 
   // Overridden from WindowImpl:
   HICON GetDefaultWindowIcon() const override;
   HICON GetSmallWindowIcon() const override;
   LRESULT OnWndProc(UINT message, WPARAM w_param, LPARAM l_param) override;
 
   // Overridden from WindowEventTarget
   LRESULT HandleMouseMessage(unsigned int message,
@@ skipping 29 matching lines @@
   // Callback if the autohide edges have changed. See
   // ViewsDelegate::GetAppbarAutohideEdges() for details.
   void OnAppbarAutohideEdgesChanged();
 
   // Can be called after the delegate has had the opportunity to set focus and
   // did not do so.
   void SetInitialFocus();
 
   // Called after the WM_ACTIVATE message has been processed by the default
   // windows procedure.
-  void PostProcessActivateMessage(int activation_state, bool minimized);
+  void PostProcessActivateMessage(
+      int activation_state,
+      bool minimized,
+      HWND window_gaining_or_losing_activation);
 
   // Enables disabled owner windows that may have been disabled due to this
   // window's modality.
   void RestoreEnabledIfNecessary();
 
   // Executes the specified SC_command.
   void ExecuteSystemMenuCommand(int command);
 
   // Start tracking all mouse events so that this window gets sent mouse leave
   // messages too.
@@ skipping 356 matching lines @@
   // receive the WM_NCLBUTTONDOWN message. We use this in the subsequent
   // WM_NCMOUSEMOVE message to see if the mouse actually moved.
   // Please refer to the HandleMouseEventInternal function for details on why
   // this is needed.
   gfx::Point caption_left_button_click_pos_;
 
   // Set to true if the left mouse button has been pressed on the caption.
   // Defaults to false.
   bool left_button_down_on_caption_;
 
+  // Set to true if the window is a background fullscreen window, i.e a
+  // fullscreen window which lost activation. Defaults to false.
+  bool background_fullscreen_hack_;
+
   // The WeakPtrFactories below must occur last in the class definition so they
   // get destroyed last.
 
   // The factory used to lookup appbar autohide edges.
   base::WeakPtrFactory<HWNDMessageHandler> autohide_factory_;
 
   // The factory used with BEGIN_SAFE_MSG_MAP_EX.
   base::WeakPtrFactory<HWNDMessageHandler> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(HWNDMessageHandler);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIN_HWND_MESSAGE_HANDLER_H_