Add source column to chrome://policy showing the origins of policies.

components/policy/core/common/configuration_policy_provider.cc

Index: components/policy/core/common/configuration_policy_provider.cc
diff --git a/components/policy/core/common/configuration_policy_provider.cc b/components/policy/core/common/configuration_policy_provider.cc
index 03fd8d7dd2accc22da17dec26372dcc034bebed8..55b3d2440648e1cfbaaefd8910cb3272bb18fb8a 100644
--- a/components/policy/core/common/configuration_policy_provider.cc
+++ b/components/policy/core/common/configuration_policy_provider.cc
@@ -13,7 +13,8 @@ namespace policy {
 ConfigurationPolicyProvider::Observer::~Observer() {}
 
 ConfigurationPolicyProvider::ConfigurationPolicyProvider()
-    : initialized_(false),
+    : source_(POLICY_SOURCE_UNKNOWN),
+      initialized_(false),
       schema_registry_(NULL) {}
 
 ConfigurationPolicyProvider::~ConfigurationPolicyProvider() {
@@ -43,15 +44,23 @@ bool ConfigurationPolicyProvider::IsInitializationComplete(
 
 void ConfigurationPolicyProvider::UpdatePolicy(
     scoped_ptr<PolicyBundle> bundle) {
-  if (bundle.get())
+  if (bundle.get()) {
     policy_bundle_.Swap(bundle.get());
-  else
+    SetPolicySources();
+  } else {
     policy_bundle_.Clear();
+  }
   FOR_EACH_OBSERVER(ConfigurationPolicyProvider::Observer,
                     observer_list_,
                     OnUpdatePolicy(this));
 }
 
+void ConfigurationPolicyProvider::SetPolicySources() {
+  for (auto& entry : policy_bundle_) {
+    entry.second->ApplySourceToEntries(source_);
+  }
+}
+
 SchemaRegistry* ConfigurationPolicyProvider::schema_registry() const {
   return schema_registry_;
 }