ComponentCloudPolicyService tracks the signin state.

chrome/browser/policy/cloud/component_cloud_policy_store.cc

Index: chrome/browser/policy/cloud/component_cloud_policy_store.cc
diff --git a/chrome/browser/policy/cloud/component_cloud_policy_store.cc b/chrome/browser/policy/cloud/component_cloud_policy_store.cc
index a6c8d629dc8cdc7f2e24230ec5ee22a64282edb1..f770eed22de35ca6309e91f7fc1421a1a8232490 100644
--- a/chrome/browser/policy/cloud/component_cloud_policy_store.cc
+++ b/chrome/browser/policy/cloud/component_cloud_policy_store.cc
@@ -231,6 +231,19 @@ void ComponentCloudPolicyStore::Purge(
     delegate_->OnComponentCloudPolicyStoreUpdated();
 }
 
+void ComponentCloudPolicyStore::Clear() {
+  for (size_t i = 0; i < arraysize(kDomains); ++i) {
+    cache_->Clear(kDomains[i].proto_cache_key);
+    cache_->Clear(kDomains[i].data_cache_key);
+  }
+  cached_hashes_.clear();
+  const PolicyBundle empty_bundle;
+  if (!policy_bundle_.Equals(empty_bundle)) {
+    policy_bundle_.Clear();
+    delegate_->OnComponentCloudPolicyStoreUpdated();
+  }
+}
+
 bool ComponentCloudPolicyStore::ValidatePolicy(
     scoped_ptr<em::PolicyFetchResponse> proto,
     PolicyNamespace* ns,