Fix log spew for "_comment..." policies.

components/policy/core/browser/configuration_policy_handler_list.cc

Index: components/policy/core/browser/configuration_policy_handler_list.cc
diff --git a/components/policy/core/browser/configuration_policy_handler_list.cc b/components/policy/core/browser/configuration_policy_handler_list.cc
index 9cdfc2aa897fbef1cd53f97489786ad6347eed67..1e9937372d1c46d25de6dfdfa6ae92fc4f685471 100644
--- a/components/policy/core/browser/configuration_policy_handler_list.cc
+++ b/components/policy/core/browser/configuration_policy_handler_list.cc
@@ -4,15 +4,23 @@
 
 #include "components/policy/core/browser/configuration_policy_handler_list.h"
 
+#include "base/bind.h"
 #include "base/stl_util.h"
 #include "components/policy/core/browser/configuration_policy_handler.h"
 #include "components/policy/core/browser/configuration_policy_handler_parameters.h"
 #include "components/policy/core/browser/policy_error_map.h"
-#include "components/policy/core/common/policy_map.h"
 #include "components/prefs/pref_value_map.h"
 #include "grit/components_strings.h"
 
 namespace policy {
+
+namespace {
+
+// Don't show errors for policies starting with that prefix.
+const char kPolicyCommentPrefix[] = "_comment";
+
+}  // namespace
+
 ConfigurationPolicyHandlerList::ConfigurationPolicyHandlerList(
     const PopulatePolicyHandlerParametersCallback& parameters_callback,
     const GetChromePolicyDetailsCallback& details_callback)
@@ -35,37 +43,64 @@ void ConfigurationPolicyHandlerList::ApplyPolicySettings(
   // This function is used both to apply the policy settings, and to check them
   // and list errors. As such it must get all the errors even if it isn't
   // applying the policies.
-  // TODO (aberent) split into two functions.
+  // TODO(aberent): split into two functions.
+  std::unique_ptr<PolicyMap> filtered_policies = policies.DeepCopy();
+  filtered_policies->EraseMatching(
+      base::Bind(&ConfigurationPolicyHandlerList::IsPlatformDevicePolicy,
+                 base::Unretained(this)));
+
   PolicyErrorMap scoped_errors;
   if (!errors)
     errors = &scoped_errors;
 
-  policy::PolicyHandlerParameters parameters;
+  PolicyHandlerParameters parameters;
   parameters_callback_.Run(&parameters);
 
-  std::vector<ConfigurationPolicyHandler*>::const_iterator handler;
-  for (handler = handlers_.begin(); handler != handlers_.end(); ++handler) {
-    if ((*handler)->CheckPolicySettings(policies, errors) && prefs) {
-      (*handler)
-          ->ApplyPolicySettingsWithParameters(policies, parameters, prefs);
+  for (auto handler : handlers_) {
+    if (handler->CheckPolicySettings(*filtered_policies, errors) && prefs) {
+      handler->ApplyPolicySettingsWithParameters(
+          *filtered_policies, parameters, prefs);
     }
   }
 
-  for (PolicyMap::const_iterator it = policies.begin();
-       it != policies.end();
-       ++it) {
-    const PolicyDetails* details =
-        details_callback_.is_null() ? NULL : details_callback_.Run(it->first);
-    if (details && details->is_deprecated)
-      errors->AddError(it->first, IDS_POLICY_DEPRECATED);
+  if (details_callback_) {
+    for (PolicyMap::const_iterator it = filtered_policies->begin();
+         it != filtered_policies->end();
+         ++it) {
+      const PolicyDetails* details = details_callback_.Run(it->first);
+      if (details && details->is_deprecated)
+        errors->AddError(it->first, IDS_POLICY_DEPRECATED);
+    }
   }
 }
 
 void ConfigurationPolicyHandlerList::PrepareForDisplaying(
     PolicyMap* policies) const {
-  std::vector<ConfigurationPolicyHandler*>::const_iterator handler;
-  for (handler = handlers_.begin(); handler != handlers_.end(); ++handler)
-    (*handler)->PrepareForDisplaying(policies);
+  for (auto handler : handlers_)
+    handler->PrepareForDisplaying(policies);
+}
+
+bool ConfigurationPolicyHandlerList::IsPlatformDevicePolicy(
+    const PolicyMap::const_iterator iter) const {
+  // Callback might be missing in tests.
+  if (!details_callback_) {
+    return false;
+  }
+  const PolicyDetails* policy_details = details_callback_.Run(iter->first);
+  if (!policy_details) {
+    const std::string prefix(kPolicyCommentPrefix);
+    if (iter->first.compare(0, prefix.length(), prefix) != 0) {
+      LOG(ERROR) << "Unknown policy: " << iter->first;
+    }
+    return false;
+  }
+  if (iter->second.source == POLICY_SOURCE_PLATFORM &&
+      policy_details->is_device_policy) {
+    // Device Policy is only implemented as Cloud Policy (not Platform Policy).
+    LOG(WARNING) << "Ignoring device platform policy: " << iter->first;
+    return true;
+  }
+  return false;
 }
 
 }  // namespace policy