AccExplorer shouldn't crash when pointed at chromium....

chrome/renderer/render_view.cc

 // Copyright (c) 2010 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 "chrome/renderer/render_view.h"
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 1233 matching lines @@
 
   last_page_id_sent_to_browser_ =
       std::max(last_page_id_sent_to_browser_, page_id_);
 
   // If we end up reusing this WebRequest (for example, due to a #ref click),
   // we don't want the transition type to persist.  Just clear it.
   navigation_state->set_transition_type(PageTransition::LINK);
 
 #if defined(OS_WIN)
   if (accessibility_.get()) {
-    // Clear accessibility info cache.
-    accessibility_->clear();
+    // Remove accessibility info cache.
+    accessibility_.reset();
   }
 #else
   // TODO(port): accessibility not yet implemented. See http://crbug.com/8288.
 #endif
 }
 
 // Tell the embedding application that the title of the active page has changed
 void RenderView::UpdateTitle(WebFrame* frame, const string16& title) {
   // Ignore all but top level navigations...
   if (!frame->parent()) {
@@ skipping 2282 matching lines @@
     const webkit_glue::WebAccessibility::InParams& in_params,
     webkit_glue::WebAccessibility::OutParams* out_params) {
 #if defined(OS_WIN)
   if (!accessibility_.get()) {
     // TODO(dglazkov): Once implemented for all ports, remove lazy
     // instantiation of accessibility_.
     accessibility_.reset(WebAccessibilityCache::create());
     accessibility_->initialize(webview());
   }
 
-  webkit_glue::WebAccessibility::GetAccObjInfo(accessibility_.get(),
-                                               in_params,
-                                               out_params);
+  out_params->return_code =
+      webkit_glue::WebAccessibility::GetAccObjInfo(accessibility_.get(),
+                                                  in_params,
+                                                  out_params);
 
 #else  // defined(OS_WIN)
   // TODO(port): accessibility not yet implemented
   NOTIMPLEMENTED();
 #endif
 }
 
 void RenderView::OnClearAccessibilityInfo(int acc_obj_id, bool clear_all) {
 #if defined(OS_WIN)
   if (!accessibility_.get()) {
@@ skipping 846 matching lines @@
                                        int32 height,
                                        uint64 io_surface_identifier) {
   Send(new ViewHostMsg_GPUPluginSetIOSurface(
       routing_id(), window, width, height, io_surface_identifier));
 }
 
 void RenderView::GPUPluginBuffersSwapped(gfx::PluginWindowHandle window) {
   Send(new ViewHostMsg_GPUPluginBuffersSwapped(routing_id(), window));
 }
 #endif