Add foundation for trimming the AffiliationDatabase.

components/password_manager/core/browser/affiliation_service.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/password_manager/core/browser/affiliation_service.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/files/file_path.h"
 #include "base/location.h"
@@ skipping 71 matching lines @@
 }
 
 void AffiliationService::TrimCache() {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(backend_);
   backend_task_runner_->PostTask(
       FROM_HERE,
       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