Added a class acting as a fake caret for accessibility.

ui/accessibility/platform/ax_fake_caret_win.cc

+// Copyright (c) 2017 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/accessibility/platform/ax_fake_caret_win.h"
+
+#include "base/logging.h"
+#include "ui/base/win/atl_module.h"
+
+namespace ui {
+
+AXFakeCaretWin::AXFakeCaretWin() {
+  ui::win::CreateATLModuleIfNeeded();
+}
+
+// static
+void AXFakeCaretWin::SetBounds(gfx::Rect bounds) {
+  bounds_ = bounds;
+}
+
+STDMETHODIMP AXFakeCaretWin::accLocation(LONG* x_left,
+                                         LONG* y_top,
+                                         LONG* width,
+                                         LONG* height,
+                                         VARIANT var_id) {
+  if (!x_left || !y_top || !width || !height)
+    return E_INVALIDARG;
+  if (var_id.vt != VT_I4 || var_id.lVal != CHILDID_SELF)
+    return E_INVALIDARG;
+
+  *x_left = static_cast<LONG>(bounds().x());
+  *y_top = static_cast<LONG>(bounds().y());
+  *width = static_cast<LONG>(bounds().width());
+  *height = static_cast<LONG>(bounds().height());
+  return S_OK;
+}
+
+STDMETHODIMP AXFakeCaretWin::get_accName(VARIANT var_id, BSTR* name) {
+  if (var_id.vt != VT_I4 || var_id.lVal != CHILDID_SELF)
+    return E_INVALIDARG;
+  if (!name)
+    return E_INVALIDARG;
+  *name = SysAllocString(OBJECT_NAME);
+  return S_OK;
+}
+
+STDMETHODIMP AXFakeCaretWin::get_accRole(VARIANT var_id, VARIANT* role) {
+  if (var_id.vt != VT_I4 || var_id.lVal != CHILDID_SELF)
+    return E_INVALIDARG;
+  if (!role)
+    return E_INVALIDARG;
+  role->vt = VT_I4;
+  role->lVal = ROLE_SYSTEM_CARET;
+  return S_OK;
+}
+
+}  // namespace ui