mojo leveldb: Add support to use in memory database.

components/leveldb/leveldb_service_unittest.cc

 // Copyright 2016 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 "base/macros.h"
 #include "components/filesystem/public/interfaces/directory.mojom.h"
 #include "components/filesystem/public/interfaces/file_system.mojom.h"
 #include "components/filesystem/public/interfaces/types.mojom.h"
 #include "components/leveldb/public/interfaces/leveldb.mojom.h"
 #include "mojo/common/common_type_converters.h"
@@ skipping 285 matching lines @@
   error = DatabaseError::OK;
   mojo::Array<uint8_t> value;
   database->GetFromSnapshot(
       invalid_snapshot,
       mojo::Array<uint8_t>::From(std::string("key")),
       Capture(&error, &value));
   ASSERT_TRUE(database.WaitForIncomingResponse());
   EXPECT_EQ(DatabaseError::INVALID_ARGUMENT, error);
 }
 
+TEST_F(LevelDBApptest, MemoryDBReadWrite) {
+  LevelDBDatabasePtr database;
+  DatabaseError error = DatabaseError::INVALID_ARGUMENT;
+  leveldb()->OpenInMemory(GetProxy(&database), Capture(&error));
+  ASSERT_TRUE(leveldb().WaitForIncomingResponse());
+  EXPECT_EQ(DatabaseError::OK, error);
+
+  // Write a key to the database.
+  error = DatabaseError::INVALID_ARGUMENT;
+  database->Put(mojo::Array<uint8_t>::From(std::string("key")),
+                mojo::Array<uint8_t>::From(std::string("value")),
+                Capture(&error));
+  ASSERT_TRUE(database.WaitForIncomingResponse());
+  EXPECT_EQ(DatabaseError::OK, error);
+
+  // Read the key back from the database.
+  error = DatabaseError::INVALID_ARGUMENT;
+  mojo::Array<uint8_t> value;
+  database->Get(mojo::Array<uint8_t>::From(std::string("key")),
+                Capture(&error, &value));
+  ASSERT_TRUE(database.WaitForIncomingResponse());
+  EXPECT_EQ(DatabaseError::OK, error);
+  EXPECT_EQ("value", value.To<std::string>());
+
+  // Delete the key from the database.
+  error = DatabaseError::INVALID_ARGUMENT;
+  database->Delete(mojo::Array<uint8_t>::From(std::string("key")),
+                   Capture(&error));
+  ASSERT_TRUE(database.WaitForIncomingResponse());
+  EXPECT_EQ(DatabaseError::OK, error);
+
+  // Read the key back from the database.
+  error = DatabaseError::INVALID_ARGUMENT;
+  value.SetToEmpty();
+  database->Get(mojo::Array<uint8_t>::From(std::string("key")),
+                Capture(&error, &value));
+  ASSERT_TRUE(database.WaitForIncomingResponse());
+  EXPECT_EQ(DatabaseError::NOT_FOUND, error);
+  EXPECT_EQ("", value.To<std::string>());
+}
+
+
 }  // namespace
 }  // namespace leveldb