Remove dependency of SSLPlatformKeyTaskRunner on single-threaded SequencedWorkerPool.

net/ssl/ssl_platform_key_win.cc

Index: net/ssl/ssl_platform_key_win.cc
diff --git a/net/ssl/ssl_platform_key_win.cc b/net/ssl/ssl_platform_key_win.cc
index 11c9d111a3d0d7bef3a5e950db77225ad18b6337..e348c5f331088aac364593c60b2b35c7cbd3add0 100644
--- a/net/ssl/ssl_platform_key_win.cc
+++ b/net/ssl/ssl_platform_key_win.cc
@@ -356,7 +356,7 @@ scoped_refptr<SSLPrivateKey> FetchClientCertPrivateKey(
     delegate.reset(new SSLPlatformKeyCAPI(prov_or_key, key_spec, max_length));
   }
   return make_scoped_refptr(new ThreadedSSLPrivateKey(
-      std::move(delegate), GetSSLPlatformKeyTaskRunner()));
+      std::move(delegate), SSLPlatformKeyTaskRunner::Get()));
 }
 
 }  // namespace net