Don't enable accessibility just because IAccessible2 APIs are queried.

content/browser/accessibility/browser_accessibility_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 "content/browser/accessibility/browser_accessibility_win.h"
 
 #include <UIAutomationClient.h>
 #include <UIAutomationCoreApi.h>
 
 #include <algorithm>
@@ skipping 3605 matching lines @@
 // IServiceProvider methods.
 //
 
 STDMETHODIMP BrowserAccessibilityWin::QueryService(REFGUID guid_service,
                                                    REFIID riid,
                                                    void** object) {
   WIN_ACCESSIBILITY_API_HISTOGRAM(UMA_API_QUERY_SERVICE);
   if (!instance_active())
     return E_FAIL;
 
-  // The system uses IAccessible APIs for many purposes, but only
-  // assistive technology like screen readers uses IAccessible2.
-  // Enable full accessibility support when IAccessible2 APIs are queried.
-  if (riid == IID_IAccessible2)
-    BrowserAccessibilityStateImpl::GetInstance()->EnableAccessibility();
-
   if (guid_service == GUID_IAccessibleContentDocument) {
     // Special Mozilla extension: return the accessible for the root document.
     // Screen readers use this to distinguish between a document loaded event
     // on the root document vs on an iframe.
     BrowserAccessibility* node = this;
     while (node->GetParent())
       node = node->GetParent()->manager()->GetRoot();
     return ToBrowserAccessibilityWin(node)->QueryInterface(
         IID_IAccessible2, object);
   }
@@ skipping 2071 matching lines @@
   return static_cast<BrowserAccessibilityWin*>(obj);
 }
 
 const BrowserAccessibilityWin*
 ToBrowserAccessibilityWin(const BrowserAccessibility* obj) {
   DCHECK(!obj || obj->IsNative());
   return static_cast<const BrowserAccessibilityWin*>(obj);
 }
 
 }  // namespace content