Add foundation for trimming the AffiliationDatabase.

components/password_manager/core/browser/affiliation_service.cc

Index: components/password_manager/core/browser/affiliation_service.cc
diff --git a/components/password_manager/core/browser/affiliation_service.cc b/components/password_manager/core/browser/affiliation_service.cc
index 0bcade91e409d79a7811a31e1eaa09278f6b3cd2..30fbe632fcb142db184f0a8440e293aa79ed7639 100644
--- a/components/password_manager/core/browser/affiliation_service.cc
+++ b/components/password_manager/core/browser/affiliation_service.cc
@@ -89,4 +89,12 @@ void AffiliationService::TrimCache() {
       base::Bind(&AffiliationBackend::TrimCache, base::Unretained(backend_)));
 }
 
+// static
+void AffiliationService::DeleteCache(
+    const base::FilePath& db_path,
+    base::SingleThreadTaskRunner* backend_task_runner) {

[vasilii, 2015/04/23 13:16:35]

AffiliationService should know the correct target thread better than the caller.

+  backend_task_runner->PostTask(
+      FROM_HERE, base::Bind(&AffiliationBackend::DeleteCache, db_path));
+}
+
 }  // namespace password_manager