Reset accessibility if it gets out of sync.

content/renderer/accessibility/renderer_accessibility_browsertest.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 "base/strings/utf_string_conversions.h"
 #include "base/time/time.h"
 #include "content/common/frame_messages.h"
 #include "content/common/view_message_enums.h"
 #include "content/public/test/render_view_test.h"
 #include "content/renderer/accessibility/renderer_accessibility_complete.h"
@@ skipping 41 matching lines @@
 
   void SetMode(AccessibilityMode mode) {
     frame()->OnSetAccessibilityMode(mode);
   }
 
   void GetLastAccEvent(
       AccessibilityHostMsg_EventParams* params) {
     const IPC::Message* message =
         sink_->GetUniqueMessageMatching(AccessibilityHostMsg_Events::ID);
     ASSERT_TRUE(message);
-    Tuple1<std::vector<AccessibilityHostMsg_EventParams> > param;
+    Tuple2<std::vector<AccessibilityHostMsg_EventParams>, int> param;
     AccessibilityHostMsg_Events::Read(message, &param);
     ASSERT_GE(param.a.size(), 1U);
     *params = param.a[0];
   }
 
   int CountAccessibilityNodesSentToBrowser() {
     AccessibilityHostMsg_EventParams event;
     GetLastAccEvent(&event);
     return event.update.nodes.size();
   }
@@ skipping 326 matching lines @@
   // ignore it.
   sink_->ClearMessages();
   accessibility->HandleAXEvent(scroll_area,
                                ui::AX_EVENT_VALUE_CHANGED);
 
   accessibility->SendPendingAccessibilityEvents();
 
   const IPC::Message* message =
       sink_->GetUniqueMessageMatching(AccessibilityHostMsg_Events::ID);
   ASSERT_TRUE(message);
-  Tuple1<std::vector<AccessibilityHostMsg_EventParams> > param;
+  Tuple2<std::vector<AccessibilityHostMsg_EventParams>, int> param;
   AccessibilityHostMsg_Events::Read(message, &param);
   ASSERT_EQ(0U, param.a.size());
 }
 
 }  // namespace content