Fix an out-of-date issue in chrome.webNavigation document.

chrome/browser/extensions/api/web_navigation/web_navigation_api_helpers.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.
 
 // Implements the Chrome Extensions WebNavigation API.
 
 #include "chrome/browser/extensions/api/web_navigation/web_navigation_api_helpers.h"
 
 #include "base/json/json_writer.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 81 matching lines @@
                          bool is_main_frame,
                          const GURL& url,
                          content::PageTransition transition_type) {
   scoped_ptr<base::ListValue> args(new base::ListValue());
   base::DictionaryValue* dict = new base::DictionaryValue();
   dict->SetInteger(keys::kTabIdKey, ExtensionTabUtil::GetTabId(web_contents));
   dict->SetString(keys::kUrlKey, url.spec());
   dict->SetInteger(keys::kProcessIdKey,
                    web_contents->GetRenderViewHost()->GetProcess()->GetID());
   dict->SetInteger(keys::kFrameIdKey, GetFrameId(is_main_frame, frame_id));
-  dict->SetString(
-      keys::kTransitionTypeKey,
-      content::PageTransitionGetCoreTransitionString(transition_type));
+  std::string transition_type_string =
+      content::PageTransitionGetCoreTransitionString(transition_type);
+  // For webNavigation API backward compatibility, keep "start_page" even after
+  // renamed to "auto_toplevel".
+  if (transition_type_string == "auto_toplevel")

[jochen (gone - plz use gerrit), 2014/01/22 11:30:02]

nit transition_type == PAGE_TRANSITION_TYPE_AUTO_TOPLEVEL

[Haojian Wu, 2014/01/22 12:05:13]

Done.

+     transition_type_string = "start_page";
+  dict->SetString(keys::kTransitionTypeKey, transition_type_string);
   base::ListValue* qualifiers = new base::ListValue();
   if (transition_type & content::PAGE_TRANSITION_CLIENT_REDIRECT)
     qualifiers->Append(new base::StringValue("client_redirect"));
   if (transition_type & content::PAGE_TRANSITION_SERVER_REDIRECT)
     qualifiers->Append(new base::StringValue("server_redirect"));
   if (transition_type & content::PAGE_TRANSITION_FORWARD_BACK)
     qualifiers->Append(new base::StringValue("forward_back"));
   if (transition_type & content::PAGE_TRANSITION_FROM_ADDRESS_BAR)
     qualifiers->Append(new base::StringValue("from_address_bar"));
   dict->Set(keys::kTransitionQualifiersKey, qualifiers);
@@ skipping 122 matching lines @@
 
   DispatchEvent(browser_context,
                 web_navigation::OnTabReplaced::kEventName,
                 args.Pass(),
                 GURL());
 }
 
 }  // namespace web_navigation_api_helpers
 
 }  // namespace extensions