base: Add basic ReadValue test to RegistryTest.

base/registry_unittest.cc

 // Copyright (c) 2010 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/registry.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace {
 
 const wchar_t kRootKey[] = L"Base_Registry_Unittest";
@@ skipping 26 matching lines @@
 
   std::wstring foo_key(kRootKey);
   foo_key += L"\\Foo";
   ASSERT_TRUE(key.Create(HKEY_CURRENT_USER, foo_key.c_str(), KEY_READ));
 
   {
     ASSERT_TRUE(key.Open(HKEY_CURRENT_USER, foo_key.c_str(),
                          KEY_READ | KEY_SET_VALUE));
 
     const wchar_t* kName = L"Bar";
-    EXPECT_TRUE(key.WriteValue(kName, L"bar"));
+    const wchar_t* kValue = L"bar";
+    EXPECT_TRUE(key.WriteValue(kName, kValue));
     EXPECT_TRUE(key.ValueExists(kName));
+    std::wstring out_value;
+    EXPECT_TRUE(key.ReadValue(kName, &out_value));
+    EXPECT_NE(out_value, L"");
+    EXPECT_STREQ(out_value.c_str(), kValue);
     EXPECT_TRUE(key.DeleteValue(kName));
   }
 }
 
 }  // namespace