Implement Windows GPO support for "dlpref" in component updater.

chrome/installer/util/google_update_settings_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/installer/util/google_update_settings.h"
 
 #include <windows.h>
 #include <shlwapi.h>  // For SHDeleteKey.
 #include <stddef.h>
 
@@ skipping 972 matching lines @@
 TEST_F(GoogleUpdateSettingsTest, ExperimentsLabelHelperSystem) {
   TestExperimentsLabelHelper(SYSTEM_INSTALL);
 }
 
 TEST_F(GoogleUpdateSettingsTest, ExperimentsLabelHelperUser) {
   TestExperimentsLabelHelper(USER_INSTALL);
 }
 
 #endif  // defined(GOOGLE_CHROME_BUILD)
 
+TEST_F(GoogleUpdateSettingsTest, GetDownloadPreference) {
+  RegKey policy_key;
+
+  if (policy_key.Open(HKEY_LOCAL_MACHINE, GoogleUpdateSettings::kPoliciesKey,
+                      KEY_SET_VALUE) == ERROR_SUCCESS) {
+    policy_key.DeleteValue(GoogleUpdateSettings::kDownloadPreference);
+  }
+  policy_key.Close();
+
+  // When no policy is present expect to return an empty string.
+  EXPECT_TRUE(GoogleUpdateSettings::GetDownloadPreference().empty());
+
+  // Expect "cacheable" when the correct policy is present.
+  EXPECT_EQ(ERROR_SUCCESS, policy_key.Create(HKEY_LOCAL_MACHINE,
+                                             GoogleUpdateSettings::kPoliciesKey,
+                                             KEY_SET_VALUE));
+  EXPECT_EQ(ERROR_SUCCESS,
+            policy_key.WriteValue(
+                GoogleUpdateSettings::kDownloadPreference,
+                GoogleUpdateSettings::kDownloadPreferenceCacheable));
+  EXPECT_STREQ(L"cacheable",
+               GoogleUpdateSettings::GetDownloadPreference().c_str());
+
+  // Expect an empty string when an unsupported policy is set.
+  EXPECT_EQ(
+      ERROR_SUCCESS,
+      policy_key.WriteValue(GoogleUpdateSettings::kDownloadPreference, L"a b"));
+  EXPECT_TRUE(GoogleUpdateSettings::GetDownloadPreference().empty());
+
+  EXPECT_EQ(
+      ERROR_SUCCESS,
+      policy_key.WriteValue(GoogleUpdateSettings::kDownloadPreference, L"<a>"));
+  EXPECT_TRUE(GoogleUpdateSettings::GetDownloadPreference().empty());
+
+  EXPECT_EQ(ERROR_SUCCESS,
+            policy_key.WriteValue(GoogleUpdateSettings::kDownloadPreference,
+                                  L"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"));

[gab, 2016/01/21 21:08:49]

base::string16(33, L'a')

to make it clearer that the test is about the size? Probably also worth testing
that base::string16(32, L'a') works.

[Sorin Jianu, 2016/01/25 20:04:58]

Done.

+  EXPECT_TRUE(GoogleUpdateSettings::GetDownloadPreference().empty());
+}
+
 // Test GoogleUpdateSettings::GetUninstallCommandLine at system- or user-level,
 // according to the param.
 class GetUninstallCommandLine : public GoogleUpdateSettingsTest,
                                 public testing::WithParamInterface<bool> {
  protected:
   static const wchar_t kDummyCommand[];
 
   void SetUp() override {
     GoogleUpdateSettingsTest::SetUp();
     system_install_ = GetParam();
@@ skipping 363 matching lines @@
         StatsState(StatsState::kSystemLevel, StatsState::MULTI_INSTALL,
                    StatsState::FALSE_SETTING, StatsState::FALSE_SETTING),
         StatsState(StatsState::kSystemLevel, StatsState::MULTI_INSTALL,
                    StatsState::FALSE_SETTING, StatsState::TRUE_SETTING),
         StatsState(StatsState::kSystemLevel, StatsState::MULTI_INSTALL,
                    StatsState::TRUE_SETTING, StatsState::NO_SETTING),
         StatsState(StatsState::kSystemLevel, StatsState::MULTI_INSTALL,
                    StatsState::TRUE_SETTING, StatsState::FALSE_SETTING),
         StatsState(StatsState::kSystemLevel, StatsState::MULTI_INSTALL,
                    StatsState::TRUE_SETTING, StatsState::TRUE_SETTING)));