Fixes for re-enabling more MSVC level 4 warnings: chrome/browser/ edition

chrome/browser/extensions/external_install_error.cc

Index: chrome/browser/extensions/external_install_error.cc
diff --git a/chrome/browser/extensions/external_install_error.cc b/chrome/browser/extensions/external_install_error.cc
index a08a40c6e01bb8ebe13549530be4c325b84c34e2..f8671e3cb014411267dad4441a0d98a48c8fc730 100644
--- a/chrome/browser/extensions/external_install_error.cc
+++ b/chrome/browser/extensions/external_install_error.cc
@@ -320,8 +320,8 @@ void ExternalInstallError::OnWebstoreRequestFailure() {
 void ExternalInstallError::OnWebstoreResponseParseSuccess(
     scoped_ptr<base::DictionaryValue> webstore_data) {
   std::string localized_user_count;
-  double average_rating;
-  int rating_count;
+  double average_rating = 0;
+  int rating_count = 0;
   if (!webstore_data->GetString(kUsersKey, &localized_user_count) ||
       !webstore_data->GetDouble(kAverageRatingKey, &average_rating) ||
       !webstore_data->GetInteger(kRatingCountKey, &rating_count)) {