Added a class acting as a fake caret for accessibility.

content/browser/renderer_host/legacy_render_widget_host_win.h

 // Copyright (c) 2014 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 CONTENT_BROWSER_RENDERER_HOST_LEGACY_RENDER_WIDGET_HOST_WIN_H_
 #define CONTENT_BROWSER_RENDERER_HOST_LEGACY_RENDER_WIDGET_HOST_WIN_H_
 
 #include <atlbase.h>
 #include <atlcrack.h>
 #include <atlwin.h>
 #include <oleacc.h>
 
 #include <memory>
 
 #include "base/macros.h"
 #include "base/win/scoped_comptr.h"
 #include "content/common/content_export.h"
 #include "ui/gfx/geometry/rect.h"
 
 namespace gfx {
 namespace win {
 class DirectManipulationHelper;
 }  // namespace win
 }  // namespace gfx
 
 namespace ui {
+class AXFakeCaretWin;
 class WindowEventTarget;
 }
 
 namespace content {
 class RenderWidgetHostViewAura;
 
 // Reasons for the existence of this class outlined below:-
 // 1. Some screen readers expect every tab / every unique web content container
 //    to be in its own HWND with class name Chrome_RenderWidgetHostHWND.
 //    With Aura there is one main HWND which comprises the whole browser window
@@ skipping 76 matching lines @@
 
   // Resizes the window to the bounds passed in.
   void SetBounds(const gfx::Rect& bounds);
 
   // The pointer to the containing RenderWidgetHostViewAura instance is passed
   // here.
   void set_host(RenderWidgetHostViewAura* host) {
     host_ = host;
   }
 
+  // Changes the position of the fake caret.
+  void MoveCaretTo(const gfx::Rect& bounds);
+
  protected:
   void OnFinalMessage(HWND hwnd) override;
 
  private:
   explicit LegacyRenderWidgetHostHWND(HWND parent);
   ~LegacyRenderWidgetHostHWND() override;
 
   bool Init();
 
   // Returns the target to which the windows input events are forwarded.
@@ skipping 19 matching lines @@
   LRESULT OnSize(UINT message, WPARAM w_param, LPARAM l_param);
   LRESULT OnWindowPosChanged(UINT message, WPARAM w_param, LPARAM l_param);
 
   base::win::ScopedComPtr<IAccessible> window_accessible_;
 
   // Set to true if we turned on mouse tracking.
   bool mouse_tracking_enabled_;
 
   RenderWidgetHostViewAura* host_;
 
+  // Some assistive software need to track the location of the caret.
+  std::unique_ptr<ui::AXFakeCaretWin> ax_fake_caret_;
+
   // This class provides functionality to register the legacy window as a
   // Direct Manipulation consumer. This allows us to support smooth scroll
   // in Chrome on Windows 10.
   std::unique_ptr<gfx::win::DirectManipulationHelper>
       direct_manipulation_helper_;
 
   DISALLOW_COPY_AND_ASSIGN(LegacyRenderWidgetHostHWND);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_LEGACY_RENDER_WIDGET_HOST_WIN_H_