Paper over a crash.

components/autofill/content/browser/content_autofill_driver_factory.cc

 // 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.
 
 #include "components/autofill/content/browser/content_autofill_driver_factory.h"
 
 #include "base/bind.h"
 #include "base/stl_util.h"
 #include "components/autofill/content/browser/content_autofill_driver.h"
 #include "components/autofill/core/browser/autofill_client.h"
@@ skipping 72 matching lines @@
 
 void ContentAutofillDriverFactory::RenderFrameDeleted(
     content::RenderFrameHost* render_frame_host) {
   delete frame_driver_map_[render_frame_host];
   frame_driver_map_.erase(render_frame_host);
 }
 
 void ContentAutofillDriverFactory::DidNavigateMainFrame(
     const content::LoadCommittedDetails& details,
     const content::FrameNavigateParams& params) {
+  // This shouldn't happen, but is causing a lot of crashes.
+  // See http://crbug.com/438951
+  if (frame_driver_map_.find(web_contents()->GetMainFrame()) ==
+          frame_driver_map_.end()) {
+    LOG(ERROR) << "Could not find ContentAutofillDriver for main frame";
+    return;
+  }
+
   frame_driver_map_[web_contents()->GetMainFrame()]->DidNavigateFrame(details,
                                                                       params);
 }
 
 void ContentAutofillDriverFactory::NavigationEntryCommitted(
     const content::LoadCommittedDetails& load_details) {
   client_->HideAutofillPopup();
 }
 
 void ContentAutofillDriverFactory::WasHidden() {
   client_->HideAutofillPopup();
 }
 
 void ContentAutofillDriverFactory::CreateDriverForFrame(
     content::RenderFrameHost* render_frame_host) {
   DCHECK(!frame_driver_map_[render_frame_host]);
   frame_driver_map_[render_frame_host] = new ContentAutofillDriver(
       render_frame_host, client_, app_locale_, enable_download_manager_);
 }
 
 }  // namespace autofill