Replaced NOTREACHED with LOG message in a couple of places

chrome/browser/webdata/keyword_table.cc

Index: chrome/browser/webdata/keyword_table.cc
diff --git a/chrome/browser/webdata/keyword_table.cc b/chrome/browser/webdata/keyword_table.cc
index 85898b8d31f63b2a09c51d31e8dbff5bf75a3f75..51c4a987f381a360647c021ee773d83baac48551 100644
--- a/chrome/browser/webdata/keyword_table.cc
+++ b/chrome/browser/webdata/keyword_table.cc
@@ -375,14 +375,14 @@ bool KeywordTable::MigrateToVersion42AddKeywordsBackupTable() {
 std::string KeywordTable::GetSignatureData() {
   int64 backup_value = 0;
   if (!meta_table_->GetValue(kDefaultSearchIDBackupKey, &backup_value)) {
-    NOTREACHED() << "Couldn't get id backup.";
+    LOG(ERROR) << "No backup id for signing.";
     return std::string();
   }
   std::string backup_data = base::Int64ToString(backup_value);
 
   std::string backup_url;
   if (!meta_table_->GetValue(kDefaultSearchBackupKey, &backup_url)) {
-    NOTREACHED() << "Couldn't get backup url";
+    LOG(ERROR) << "No backup for signing.";
     return std::string();
   }
   backup_data += backup_url;