Initialize OSCrypt with a TaskRunner on the main thread

components/os_crypt/os_crypt_linux.cc

 // Copyright 2016 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/os_crypt/os_crypt.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <iterator>
@@ skipping 208 matching lines @@
 }
 
 // static
 void OSCrypt::SetProductName(const std::string& product_name) {
   // Setting the product name makes no sense after initializing.
   DCHECK(!g_cache.Get().is_key_storage_cached);
 
   KeyStorageLinux::SetProductName(product_name);
 }
 
+// static
+void OSCrypt::SetMainThreadRunner(
+    scoped_refptr<base::SingleThreadTaskRunner> main_thread_runner) {
+  // Setting the task runner makes no sense after initializing.
+  DCHECK(!g_cache.Get().is_key_storage_cached);
+
+  KeyStorageLinux::SetMainThreadRunner(main_thread_runner);
+}
+
 void UseMockKeyStorageForTesting(KeyStorageLinux* (*get_key_storage_mock)(),
                                  std::string* (*get_password_v11_mock)()) {
   // Save the real implementation to restore it later.
   static bool is_get_password_saved = false;
   static std::string* (*get_password_save[arraysize(g_get_password)])();
   if (!is_get_password_saved) {
     std::copy(std::begin(g_get_password), std::end(g_get_password),
               std::begin(get_password_save));
     is_get_password_saved = true;
   }
 
   if (get_key_storage_mock && get_password_v11_mock) {
     // Bypass calling KeyStorage::CreateService and caching of the key for V11
     g_get_password[Version::V11] = get_password_v11_mock;
     // OSCrypt will determine the encryption version by checking if a
     // |KeyStorage| instance can be created. Enable V11 by returning the mock.
     g_key_storage_provider = get_key_storage_mock;
   } else {
     // Restore real implementation
     std::copy(std::begin(get_password_save), std::end(get_password_save),
               std::begin(g_get_password));
   }
 }