Get rid of the 1-pixel client inset hack.

ui/views/widget/desktop_aura/desktop_root_window_host_win.cc

Index: ui/views/widget/desktop_aura/desktop_root_window_host_win.cc
diff --git a/ui/views/widget/desktop_aura/desktop_root_window_host_win.cc b/ui/views/widget/desktop_aura/desktop_root_window_host_win.cc
index 22ad0f208ccce57f3460176feccf5018ce97c085..aa7dca0fe4aed9cdf600f6db0d2457276cc88639 100644
--- a/ui/views/widget/desktop_aura/desktop_root_window_host_win.cc
+++ b/ui/views/widget/desktop_aura/desktop_root_window_host_win.cc
@@ -749,6 +749,7 @@ void DesktopRootWindowHostWin::HandleClientSizeChanged(
 }
 
 void DesktopRootWindowHostWin::HandleFrameChanged() {
+  SetWindowTransparency();
   // Replace the frame and layout the contents.
   GetWidget()->non_client_view()->UpdateFrame(true);
 }
@@ -888,6 +889,7 @@ void DesktopRootWindowHostWin::SetWindowTransparency() {
   bool transparent = ShouldUseNativeFrame() && !IsFullscreen();
   root_window_->compositor()->SetHostHasTransparentBackground(transparent);
   root_window_->window()->SetTransparent(transparent);
+  content_window_->SetTransparent(transparent);
 }
 
 bool DesktopRootWindowHostWin::IsModalWindowActive() const {