ComponentCloudPolicyService tracks the signin state.

chrome/browser/policy/cloud/resource_cache.cc

Index: chrome/browser/policy/cloud/resource_cache.cc
diff --git a/chrome/browser/policy/cloud/resource_cache.cc b/chrome/browser/policy/cloud/resource_cache.cc
index b38eb64089c579e2070804e6b95b41a88ae5acf3..998b728dad3795bc1cf49618489bd1e7aaf16ea2 100644
--- a/chrome/browser/policy/cloud/resource_cache.cc
+++ b/chrome/browser/policy/cloud/resource_cache.cc
@@ -137,6 +137,13 @@ void ResourceCache::Delete(const std::string& key, const std::string& subkey) {
   base::DeleteFile(subkey_path.DirName(), false);
 }
 
+void ResourceCache::Clear(const std::string& key) {
+  DCHECK(task_runner_->RunsTasksOnCurrentThread());
+  base::FilePath key_path;
+  if (VerifyKeyPath(key, false, &key_path))
+    base::DeleteFile(key_path, true);
+}
+
 void ResourceCache::FilterSubkeys(const std::string& key,
                                   const SubkeyFilter& test) {
   DCHECK(task_runner_->RunsTasksOnCurrentThread());