Another attempt at fixing the fullscreen issues with Chrome.

ui/views/win/fullscreen_handler.cc

Index: ui/views/win/fullscreen_handler.cc
diff --git a/ui/views/win/fullscreen_handler.cc b/ui/views/win/fullscreen_handler.cc
index 89581d79d06dbae1ebe657ede9aca043725cba7f..d6013f765b987bc6ee2627ebc62511bea9f32770 100644
--- a/ui/views/win/fullscreen_handler.cc
+++ b/ui/views/win/fullscreen_handler.cc
@@ -39,6 +39,13 @@ gfx::Rect FullscreenHandler::GetRestoreBounds() const {
 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.
@@ -85,6 +92,13 @@ void FullscreenHandler::SetFullscreenImpl(bool fullscreen) {
                  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