Another attempt at fixing the fullscreen issues with Chrome.

ui/views/win/fullscreen_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/fullscreen_handler.h"
 
 #include <memory>
 
 #include "base/logging.h"
 #include "base/win/win_util.h"
@@ skipping 21 matching lines @@
 gfx::Rect FullscreenHandler::GetRestoreBounds() const {
   return gfx::Rect(saved_window_info_.window_rect);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // FullscreenHandler, private:
 
 void FullscreenHandler::SetFullscreenImpl(bool fullscreen) {
   std::unique_ptr<ScopedFullscreenVisibility> visibility;
 
+  if (!task_bar_list_) {

[msw, 2017/07/06 19:33:52]

optional nit: move this down to just above the task_bar_list_ usage.

[ananta, 2017/07/06 20:03:17]

Done.

+    HRESULT hr = ::CoCreateInstance(CLSID_TaskbarList, NULL,
+                                    CLSCTX_INPROC_SERVER,
+                                    IID_PPV_ARGS(&task_bar_list_));
+    CHECK(SUCCEEDED(hr));
+  }
+
   // With Aero enabled disabling the visibility causes the window to disappear
   // for several frames, which looks worse than doing other updates
   // non-atomically.
   if (!ui::win::IsAeroGlassEnabled())
     visibility.reset(new ScopedFullscreenVisibility(hwnd_));
 
   // Save current window state if not already fullscreen.
   if (!fullscreen_) {
     saved_window_info_.style = GetWindowLong(hwnd_, GWL_STYLE);
     saved_window_info_.ex_style = GetWindowLong(hwnd_, GWL_EXSTYLE);
@@ skipping 26 matching lines @@
     // repainted.  Better-looking methods welcome.
     SetWindowLong(hwnd_, GWL_STYLE, saved_window_info_.style);
     SetWindowLong(hwnd_, GWL_EXSTYLE, saved_window_info_.ex_style);
 
     // On restore, resize to the previous saved rect size.
     gfx::Rect new_rect(saved_window_info_.window_rect);
     SetWindowPos(hwnd_, NULL, new_rect.x(), new_rect.y(), new_rect.width(),
                  new_rect.height(),
                  SWP_NOZORDER | SWP_NOACTIVATE | SWP_FRAMECHANGED);
   }
+
+  // As per MSDN marking the window as fullscreen should ensure that the
+  // taskbar is moved to the bottom of the Z- order when the fullscreen window

[msw, 2017/07/06 19:33:52]

nit: no space after hyphen ('Z-order')

[ananta, 2017/07/06 20:03:17]

Thanks done.

+  // is activated. If the window is not fullscreen, the Shell falls back to
+  // heuristics to determine how the window should be treated, which means
+  // that it could still consider the window as fullscreen. :(
+  task_bar_list_->MarkFullscreenWindow(hwnd_, !!fullscreen);
 }
 
 }  // namespace views