Add a mutator for the MetricReportingEnabled policy

This changes the level of the policy to recommended if it is set to
enabled and the level isn't recommended to make the policy compliant
with the privacy expectations of the browser.

Bug: 1155602
Change-Id: I133a7cd58a729fae06c151c742569cf5c80cb500
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2575056
Commit-Queue: Julian Pastarmov <pastarmovj@chromium.org>
Reviewed-by: Yann Dago <ydago@chromium.org>
Cr-Commit-Position: refs/heads/master@{#835346}

components/policy/core/common/policy_service_impl.cc

@@ -156,6 +156,18 @@ void RemapRenamedPolicies(PolicyMap* policies) {
   }
 }
 
+// Metrics should not be enforced so if this policy is set as mandatory
+// downgrade it to a recommended level policy.
+void DowngradeMetricsReportingToRecommendedPolicy(PolicyMap* policies) {
+  PolicyMap::Entry* policy =
+      policies->GetMutable(policy::key::kMetricsReportingEnabled);
+  if (policy && policy->level != POLICY_LEVEL_RECOMMENDED && policy->value() &&
+      policy->value()->is_bool() && policy->value()->GetBool()) {
+    policy->level = POLICY_LEVEL_RECOMMENDED;
+    policy->AddError(IDS_POLICY_IGNORED_MANDATORY_REPORTING_POLICY);
+  }
+}
+
 // Returns the string values of |policy|. Returns an empty set if the values are
 // not strings.
 base::flat_set<std::string> GetStringListPolicyItems(
@@ -357,6 +369,8 @@ void PolicyServiceImpl::MergeAndTriggerUpdates() {
     provided_bundle.CopyFrom(provider->policies());
     RemapProxyPolicies(&provided_bundle.Get(chrome_namespace));
     RemapRenamedPolicies(&provided_bundle.Get(chrome_namespace));
+    DowngradeMetricsReportingToRecommendedPolicy(
+        &provided_bundle.Get(chrome_namespace));
     bundle.MergeFrom(provided_bundle);
   }
 

components/policy_strings.grdp

@@ -528,6 +528,9 @@ Additional details:
   <message name="IDS_POLICY_INVALID_VALUE"  desc="Text explaining that the policy value is invalid">
     Policy value is not valid.
   </message>
+  <message name="IDS_POLICY_IGNORED_MANDATORY_REPORTING_POLICY" desc="Text explaining that the policy MetricsReportingEnabled can not be forced to enabled anymore">
+    This policy cannot be set to "True" and be mandatory, therefore it was changed to recommended.
+  </message>
   <if expr="not is_macosx">
     <message name="IDS_POLICY_SPELLCHECK_UNKNOWN_LANGUAGE" desc="Warning message in the policy summary page for the spellcheck policies when a language is unrecognized or unsupported.">
       List entry "<ph name="LANGUAGE_ID">$1<ex>xx-YY</ex></ph>": Unknown or unsupported language.

components/policy_strings_grdp/IDS_POLICY_IGNORED_MANDATORY_REPORTING_POLICY.png.sha1

+3e564aab90fac31f292882920b85070a7cfa3fd2
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