Make ProtoDatabase properly handle failed Init

components/leveldb_proto/leveldb_database.cc

Index: components/leveldb_proto/leveldb_database.cc
diff --git a/components/leveldb_proto/leveldb_database.cc b/components/leveldb_proto/leveldb_database.cc
index 65d68a9d138da76dbfd6274abb05e4b1d19f2f2f..45f220e9576c565e6dfcbbdec81d34def93849c5 100644
--- a/components/leveldb_proto/leveldb_database.cc
+++ b/components/leveldb_proto/leveldb_database.cc
@@ -23,14 +23,13 @@ namespace leveldb_proto {
 
 LevelDB::LevelDB() {}
 
-LevelDB::~LevelDB() { DFAKE_SCOPED_LOCK(thread_checker_); }
-
-bool LevelDB::Init(const base::FilePath& database_dir) {
+LevelDB::~LevelDB() {
   DFAKE_SCOPED_LOCK(thread_checker_);
+}
 
-  leveldb::Options options;
-  options.create_if_missing = true;
-  options.max_open_files = 0;  // Use minimum.
+bool LevelDB::InitWithOptions(const base::FilePath& database_dir,
+                              const leveldb::Options& options) {
+  DFAKE_SCOPED_LOCK(thread_checker_);
 
   std::string path = database_dir.AsUTF8Unsafe();
 
@@ -52,9 +51,19 @@ bool LevelDB::Init(const base::FilePath& database_dir) {
   return false;
 }
 
+bool LevelDB::Init(const base::FilePath& database_dir) {
+  leveldb::Options options;
+  options.create_if_missing = true;
+  options.max_open_files = 0;  // Use minimum.
+  return InitWithOptions(database_dir, options);
+}
+
 bool LevelDB::Save(const base::StringPairs& entries_to_save,
                    const std::vector<std::string>& keys_to_remove) {
   DFAKE_SCOPED_LOCK(thread_checker_);
+  if (!db_) {
+    return false;
+  }
 
   leveldb::WriteBatch updates;
   for (base::StringPairs::const_iterator it = entries_to_save.begin();
@@ -79,6 +88,9 @@ bool LevelDB::Save(const base::StringPairs& entries_to_save,
 
 bool LevelDB::Load(std::vector<std::string>* entries) {
   DFAKE_SCOPED_LOCK(thread_checker_);
+  if (!db_) {
+    return false;
+  }
 
   leveldb::ReadOptions options;
   scoped_ptr<leveldb::Iterator> db_iterator(db_->NewIterator(options));