Revert of Added a system caret used for accessibility on Windows.

ui/views/widget/desktop_aura/desktop_window_tree_host_win.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/widget/desktop_aura/desktop_window_tree_host_win.h"
 
 #include "base/memory/ptr_util.h"
 #include "third_party/skia/include/core/SkPath.h"
 #include "third_party/skia/include/core/SkRegion.h"
 #include "ui/aura/client/aura_constants.h"
@@ skipping 582 matching lines @@
 }
 
 void DesktopWindowTreeHostWin::OnWindowHidingAnimationCompleted() {
   if (pending_close_)
     message_handler_->Close();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // DesktopWindowTreeHostWin, HWNDMessageHandlerDelegate implementation:
 
-ui::InputMethod* DesktopWindowTreeHostWin::GetHWNDMessageDelegateInputMethod() {
-  return GetInputMethod();
-}
-
 bool DesktopWindowTreeHostWin::HasNonClientView() const {
   return has_non_client_view_;
 }
 
 FrameMode DesktopWindowTreeHostWin::GetFrameMode() const {
   return GetWidget()->ShouldUseNativeFrame() ? FrameMode::SYSTEM_DRAWN
                                              : FrameMode::CUSTOM_DRAWN;
 }
 
 bool DesktopWindowTreeHostWin::HasFrame() const {
@@ skipping 382 matching lines @@
 
 // static
 DesktopWindowTreeHost* DesktopWindowTreeHost::Create(
     internal::NativeWidgetDelegate* native_widget_delegate,
     DesktopNativeWidgetAura* desktop_native_widget_aura) {
   return new DesktopWindowTreeHostWin(native_widget_delegate,
                                       desktop_native_widget_aura);
 }
 
 }  // namespace views