Reland "Merge old and new list policies that were renamed"

This is a reland of b53e31ad

Original change's description:
> Merge old and new list policies that were renamed
>
> This change moves migrating of renamed policies from the PolicyHandler
> to a PolicyMigrator that happens right after the PolicyMerger has run.
> This guarantees that list policies can be properly merged between
> sources even if different sources provide different naming.
>
> BUG=1138572
> TEST=browser_tests:PolicyPrefsTest.PolicyToPrefsMapping
>
> Change-Id: Ibe335176ef52dabbe09c076ba57ae04d1c67c1c6
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2507771
> Commit-Queue: Julian Pastarmov <pastarmovj@chromium.org>
> Reviewed-by: Owen Min <zmin@chromium.org>
> Reviewed-by: Yann Dago <ydago@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#826903}

Bug: 1138572
Change-Id: I410d65abdbcf81a07ca578bec619fcbcd933fce3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2536880Reviewed-by: Owen Min <zmin@chromium.org>
Reviewed-by: Yann Dago <ydago@chromium.org>
Auto-Submit: Julian Pastarmov <pastarmovj@chromium.org>
Commit-Queue: Julian Pastarmov <pastarmovj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#827365}

chrome/browser/policy/cloud/cloud_policy_browsertest.cc

@@ -138,7 +138,7 @@ std::string GetTestPolicy(const char* homepage, int key_version) {
       "    \"mandatory\": {"
       "      \"ShowHomeButton\": true,"
       "      \"RestoreOnStartup\": 4,"
-      "      \"URLBlacklist\": [ \"dev.chromium.org\", \"youtube.com\" ],"
+      "      \"URLBlocklist\": [ \"dev.chromium.org\", \"youtube.com\" ],"
       "      \"MaxInvalidationFetchDelay\": 1000"
       "    },"
       "    \"recommended\": {"
@@ -167,7 +167,7 @@ void GetExpectedTestPolicy(PolicyMap* expected, const char* homepage) {
   base::ListValue list;
   list.AppendString("dev.chromium.org");
   list.AppendString("youtube.com");
-  expected->Set(key::kURLBlacklist, POLICY_LEVEL_MANDATORY, POLICY_SCOPE_USER,
+  expected->Set(key::kURLBlocklist, POLICY_LEVEL_MANDATORY, POLICY_SCOPE_USER,
                 POLICY_SOURCE_CLOUD, list.Clone(), nullptr);
   expected->Set(key::kMaxInvalidationFetchDelay, POLICY_LEVEL_MANDATORY,
                 POLICY_SCOPE_USER, POLICY_SOURCE_CLOUD, base::Value(1000),

chrome/browser/policy/restore_on_startup_policy_browsertest.cc

@@ -125,7 +125,7 @@ class RestoreOnStartupPolicyTest : public PolicyTest,
     base::Value urls(base::Value::Type::LIST);
     for (const auto* url_string : kRestoredURLs)
       urls.Append(url_string);
-    policies.Set(key::kURLBlacklist, POLICY_LEVEL_MANDATORY, POLICY_SCOPE_USER,
+    policies.Set(key::kURLBlocklist, POLICY_LEVEL_MANDATORY, POLICY_SCOPE_USER,
                  POLICY_SOURCE_CLOUD, std::move(urls), nullptr);
     provider_.UpdateChromePolicy(policies);
     // This should restore the tabs opened at PRE_RunTest below, yet all should

components/policy/core/common/policy_service_impl.cc

@@ -18,6 +18,7 @@
 #include "base/stl_util.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/values.h"
+#include "build/build_config.h"
 #include "components/policy/core/common/features.h"
 #include "components/policy/core/common/policy_bundle.h"
 #include "components/policy/core/common/policy_map.h"
@@ -25,6 +26,7 @@
 #include "components/policy/core/common/policy_types.h"
 #include "components/policy/core/common/values_util.h"
 #include "components/policy/policy_constants.h"
+#include "extensions/buildflags/buildflags.h"
 
 #if defined(OS_ANDROID)
 #include "components/policy/core/common/android/policy_service_android.h"
@@ -79,6 +81,75 @@ void RemapProxyPolicies(PolicyMap* policies) {
   }
 }
 
+// Maps the separate policies for proxy settings into a single Dictionary
+// policy. This allows to keep the logic of merging policies from different
+// sources simple, as all separate proxy policies should be considered as a
+// single whole during merging.
+void RemapRenamedPolicies(PolicyMap* policies) {
+  // For all renamed policies we need to explicitly merge the value of the
+  // old policy with the new one or else merging will not be carried over
+  // if desired.
+  base::Value* merge_list =
+      policies->GetMutableValue(key::kPolicyListMultipleSourceMergeList);
+  base::flat_set<std::string> policy_lists_to_merge =
+      policy::ValueToStringSet(merge_list);
+  const std::vector<std::pair<const char*, const char*>> renamed_policies = {{
+      {policy::key::kSafeBrowsingWhitelistDomains,
+       policy::key::kSafeBrowsingAllowlistDomains},
+      {policy::key::kSpellcheckLanguageBlacklist,
+       policy::key::kSpellcheckLanguageBlocklist},
+      {policy::key::kURLBlacklist, policy::key::kURLBlocklist},
+      {policy::key::kURLWhitelist, policy::key::kURLAllowlist},
+#if !defined(OS_ANDROID)
+      {policy::key::kAutoplayWhitelist, policy::key::kAutoplayAllowlist},
+#endif  // !defined(OS_ANDROID)
+#if BUILDFLAG(ENABLE_EXTENSIONS)
+      {policy::key::kExtensionInstallBlacklist,
+       policy::key::kExtensionInstallBlocklist},
+      {policy::key::kExtensionInstallWhitelist,
+       policy::key::kExtensionInstallAllowlist},
+      {policy::key::kNativeMessagingBlacklist,
+       policy::key::kNativeMessagingBlocklist},
+      {policy::key::kNativeMessagingWhitelist,
+       policy::key::kNativeMessagingAllowlist},
+#endif  // BUILDFLAG(ENABLE_EXTENSIONS)
+#if defined(OS_CHROMEOS)
+      {policy::key::kAttestationExtensionWhitelist,
+       policy::key::kAttestationExtensionAllowlist},
+      {policy::key::kExternalPrintServersWhitelist,
+       policy::key::kExternalPrintServersAllowlist},
+      {policy::key::kNativePrintersBulkBlacklist,
+       policy::key::kPrintersBulkBlocklist},
+      {policy::key::kNativePrintersBulkWhitelist,
+       policy::key::kPrintersBulkAllowlist},
+      {policy::key::kPerAppTimeLimitsWhitelist,
+       policy::key::kPerAppTimeLimitsAllowlist},
+      {policy::key::kQuickUnlockModeWhitelist,
+       policy::key::kQuickUnlockModeAllowlist},
+      {policy::key::kNoteTakingAppsLockScreenWhitelist,
+       policy::key::kNoteTakingAppsLockScreenAllowlist},
+#if defined(USE_CUPS)
+      {policy::key::kPrintingAPIExtensionsWhitelist,
+       policy::key::kPrintingAPIExtensionsAllowlist},
+#endif  // defined(USE_CUPS)
+#endif  // defined(OS_CHROMEOS)
+  }};
+  for (const auto& policy_pair : renamed_policies) {
+    PolicyMap::Entry* old_policy = policies->GetMutable(policy_pair.first);
+    const PolicyMap::Entry* new_policy = policies->Get(policy_pair.second);
+    if (old_policy && !new_policy) {
+      PolicyMap::Entry policy_entry = old_policy->DeepCopy();
+      // TODO(pastarmovj): Re-add the policy errors in a way that does not
+      // depend on resources being loaded that early.
+      policies->Set(policy_pair.second, std::move(policy_entry));
+    }
+    if (policy_lists_to_merge.contains(policy_pair.first) &&
+        !policy_lists_to_merge.contains(policy_pair.second)) {
+      merge_list->Append(base::Value(policy_pair.second));
+    }
+  }
+}
+
 // Returns the string values of |policy|. Returns an empty set if the values are
 // not strings.
 base::flat_set<std::string> GetStringListPolicyItems(
@@ -279,6 +350,7 @@ void PolicyServiceImpl::MergeAndTriggerUpdates() {
     PolicyBundle provided_bundle;
     provided_bundle.CopyFrom(provider->policies());
     RemapProxyPolicies(&provided_bundle.Get(chrome_namespace));
+    RemapRenamedPolicies(&provided_bundle.Get(chrome_namespace));
     bundle.MergeFrom(provided_bundle);
   }