Make some of the search engine configuration data from master_preferences optional.

chrome/browser/search_engines/template_url_prepopulate_data.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 "chrome/browser/search_engines/template_url_prepopulate_data.h"
 
 #if defined(OS_POSIX) && !defined(OS_MACOSX)
 #include <locale.h>
 #endif
 
@@ skipping 3542 matching lines @@
 void GetPrepopulatedTemplateFromPrefs(Profile* profile,
                                       std::vector<TemplateURL*>* t_urls) {
   if (!profile)
     return;
 
   const ListValue* list =
       profile->GetPrefs()->GetList(prefs::kSearchProviderOverrides);
   if (!list)
     return;
 
   string16 name;

[Peter Kasting, 2012/10/16 17:48:32]

Nit: I suggest moving all these declarations inside the loop to scope them as
narrowly as possible.  We don't care about the tiny efficiency loss.

[Joao da Silva, 2012/10/16 18:53:36]

Done.

   string16 keyword;
   std::string search_url;
-  std::string suggest_url;
-  std::string instant_url;
-  const ListValue* alternate_urls = NULL;
-  std::string favicon_url;
+  std::string favicon;

[Peter Kasting, 2012/10/16 17:48:32]

Nit: Leave this named "favicon_url"

[Joao da Silva, 2012/10/16 18:53:36]

But but but then the line is 81 chars! (Done!)

   std::string encoding;
   int id;
+  const ListValue kEmptyList;

[Peter Kasting, 2012/10/16 17:48:32]

Nit: This one I'd declare just above |alternate_urls| as

  ListValue empty_list;
  const ListValue* alternate_urls = &empty_list;

[Joao da Silva, 2012/10/16 18:53:36]

Done.

 
   size_t num_engines = list->GetSize();
   for (size_t i = 0; i != num_engines; ++i) {
     const DictionaryValue* engine;
+    // The following fields are required for each search engine configuration.
     if (list->GetDictionary(i, &engine) &&
-        engine->GetString("name", &name) &&
-        engine->GetString("keyword", &keyword) &&
-        engine->GetString("search_url", &search_url) &&
-        engine->GetString("suggest_url", &suggest_url) &&
-        engine->GetString("instant_url", &instant_url) &&
-        engine->GetList("alternate_urls", &alternate_urls) &&
-        engine->GetString("favicon_url", &favicon_url) &&
-        engine->GetString("encoding", &encoding) &&
+        engine->GetString("name", &name) && !name.empty() &&
+        engine->GetString("keyword", &keyword) && !keyword.empty() &&
+        engine->GetString("search_url", &search_url) && !search_url.empty() &&
+        engine->GetString("favicon_url", &favicon) && !favicon.empty() &&
+        engine->GetString("encoding", &encoding) && !encoding.empty() &&
         engine->GetInteger("id", &id)) {
-      // These next fields are not allowed to be empty.
-      if (name.empty() || keyword.empty() || search_url.empty() ||
-          favicon_url.empty() || encoding.empty())
-        return;
-    } else {
-      // Got a parsing error. No big deal.
-      continue;
+      // These fields are optional.
+      std::string suggest_url;
+      std::string instant_url;
+      const ListValue* alternate_urls = &kEmptyList;
+      engine->GetString("suggest_url", &suggest_url);
+      engine->GetString("instant_url", &instant_url);
+      engine->GetList("alternate_urls", &alternate_urls);
+      t_urls->push_back(MakePrepopulatedTemplateURL(profile, name, keyword,
+          search_url, suggest_url, instant_url, *alternate_urls, favicon,
+          encoding, id));
     }
-    t_urls->push_back(MakePrepopulatedTemplateURL(profile, name, keyword,
-        search_url, suggest_url, instant_url, *alternate_urls, favicon_url,
-        encoding, id));
   }
 }
 
 // The caller owns the returned TemplateURL.
 TemplateURL* MakePrepopulatedTemplateURLFromPrepopulateEngine(
     Profile* profile,
     const PrepopulatedEngine& engine) {
 
   // Use an empty list if there are no alternate_urls.
   ListValue empty_list;
@@ skipping 104 matching lines @@
     g_country_code_at_install = kCountryIDUnknown;
   } else {
     g_country_code_at_install =
         CountryCharsToCountryIDWithUpdate(country_code[0], country_code[1]);
   }
 }
 
 #endif
 
 }  // namespace TemplateURLPrepopulateData