Fix queued writes in DeviceSettingsProvider.

chrome/browser/chromeos/settings/device_settings_provider_unittest.cc

 // Copyright (c) 2012 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 "chrome/browser/chromeos/settings/device_settings_provider.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 186 matching lines @@
                   metrics_enabled().metrics_enabled());
 
   // Verify the change has been applied.
   const base::Value* saved_value = provider_->Get(kStatsReportingPref);
   ASSERT_TRUE(saved_value);
   bool bool_value;
   EXPECT_TRUE(saved_value->GetAsBoolean(&bool_value));
   EXPECT_TRUE(bool_value);
 }
 
+TEST_F(DeviceSettingsProviderTest, SetPrefTwice) {
+  owner_key_util_->SetPrivateKey(policy_.signing_key());
+  device_settings_service_.SetUsername(policy_.policy_data().username());
+  device_settings_test_helper_.Flush();
+
+  EXPECT_CALL(*this, SettingChanged(_)).Times(AnyNumber());
+
+  base::StringValue value1("beta");
+  provider_->Set(kReleaseChannel, value1);
+  base::StringValue value2("dev");
+  provider_->Set(kReleaseChannel, value2);
+
+  // Let the changes propagate through the system.
+  device_settings_test_helper_.set_policy_blob(std::string());
+  device_settings_test_helper_.Flush();
+
+  // Verify the second change has been applied.
+  const base::Value* saved_value = provider_->Get(kReleaseChannel);
+  EXPECT_TRUE(value2.Equals(saved_value));
+
+  Mock::VerifyAndClearExpectations(this);
+}
+
 TEST_F(DeviceSettingsProviderTest, PolicyRetrievalFailedBadSignature) {
   owner_key_util_->SetPublicKeyFromPrivateKey(policy_.signing_key());
   policy_.policy().set_policy_data_signature("bad signature");
   device_settings_test_helper_.set_policy_blob(policy_.GetBlob());
 
   device_settings_service_.Load();
   device_settings_test_helper_.Flush();
 
   // Verify that the cached settings blob is not "trusted".
   EXPECT_EQ(DeviceSettingsService::STORE_VALIDATION_ERROR,
@@ skipping 60 matching lines @@
 
   // Verify that migration has kicked in.
   const base::Value* saved_value = provider_->Get(kStatsReportingPref);
   ASSERT_TRUE(saved_value);
   bool bool_value;
   EXPECT_TRUE(saved_value->GetAsBoolean(&bool_value));
   EXPECT_FALSE(bool_value);
 }
 
 } // namespace chromeos