base/win: Add documentation to RegKey::Read/Write functions.

chrome/installer/util/installer_state_unittest.cc

Index: chrome/installer/util/installer_state_unittest.cc
diff --git a/chrome/installer/util/installer_state_unittest.cc b/chrome/installer/util/installer_state_unittest.cc
index 14dec6da3eb6985f82c906ce52339db39ebf6208..51e6c7b8f700091dea163bd58d49452b5d50e6cb 100644
--- a/chrome/installer/util/installer_state_unittest.cc
+++ b/chrome/installer/util/installer_state_unittest.cc
@@ -396,10 +396,10 @@ TEST_F(InstallerStateTest, InstallerResult) {
     EXPECT_EQ(ERROR_SUCCESS,
         key.Open(root, distribution->GetStateKey().c_str(), KEY_READ));
     EXPECT_EQ(ERROR_SUCCESS,
-        key.ReadValueDW(installer::kInstallerResult, &dw_value));
+        key.ReadValue(installer::kInstallerResult, &dw_value));
     EXPECT_EQ(static_cast<DWORD>(0), dw_value);
     EXPECT_EQ(ERROR_SUCCESS,
-        key.ReadValueDW(installer::kInstallerError, &dw_value));
+        key.ReadValue(installer::kInstallerError, &dw_value));
     EXPECT_EQ(static_cast<DWORD>(installer::FIRST_INSTALL_SUCCESS), dw_value);
     EXPECT_EQ(ERROR_SUCCESS,
         key.ReadValue(installer::kInstallerResultUIString, &value));