Revert of Migrate accessibility from RenderView to RenderFrame.

content/common/accessibility_mode_enums.h

-// Copyright 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_COMMON_ACCESSIBILITY_MODE_ENUMS_H_
-#define CONTENT_COMMON_ACCESSIBILITY_MODE_ENUMS_H_
-
-// Note: keep enums in content/browser/resources/accessibility/accessibility.js
-// in sync with these two enums.
-enum AccessibilityModeFlag {
-  // Accessibility updates are processed to create platform trees and events are
-  // passed to platform APIs in the browser.
-  AccessibilityModeFlagPlatform = 1 << 0,
-
-  // Accessibility is on, and the full tree is computed. If this flag is off,
-  // only limited information about editable text nodes is sent to the browser
-  // process. Useful for implementing limited UIA on tablets.
-  AccessibilityModeFlagFullTree = 1 << 1,
-};
-
-enum AccessibilityMode {
-  // All accessibility is off.
-  AccessibilityModeOff = 0,
-
-  // Renderer accessibility is on, platform APIs are called, but only limited
-  // information is available (see AccessibilityModeFlagEditableTextOnly).
-  AccessibilityModeEditableTextOnly = AccessibilityModeFlagPlatform,
-
-  // Renderer accessibility is on, and platform APIs are called.
-  AccessibilityModeComplete =
-      AccessibilityModeFlagPlatform | AccessibilityModeFlagFullTree,
-
-  // Renderer accessibility is on, and events are passed to any extensions
-  // requesting automation, but not to platform accessibility.
-  AccessibilityModeTreeOnly = AccessibilityModeFlagFullTree,
-};
-
-#endif  // CONTENT_COMMON_ACCESSIBILITY_MODE_ENUMS_H_