Set longer timeout for DLC installation

Preloading times out for large DLC images because the hash takes too
long. F20 provisioning can resolve this issue for tests that currently
depend on preloadable DLC images.

BUG=b:164310699
TEST=unit_tests # --filter=*Dlc*

Change-Id: I919004d7081de6e93aa26113f931ac1c0154e641
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2381052
Commit-Queue: Jae Hoon Kim <kimjae@chromium.org>
Commit-Queue: Steven Bennetts <stevenjb@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Auto-Submit: Jae Hoon Kim <kimjae@chromium.org>
Cr-Commit-Position: refs/heads/master@{#803188}

chromeos/dbus/dlcservice/dlcservice_client.cc

@@ -130,8 +130,12 @@ class DlcserviceClientImpl : public DlcserviceClient {
     writer.AppendString(dlc_id);
 
     VLOG(1) << "Requesting to install DLC(s).";
+    // TODO(b/166782419): dlcservice hashes preloadable DLC images which can
+    // cause timeouts during preloads. Transitioning into F20 will fix this as
+    // preloading will be deprecated.
+    constexpr int timeout_ms = 5 * 60 * 1000;
     dlcservice_proxy_->CallMethodWithErrorResponse(
-        &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+        &method_call, timeout_ms,
         base::BindOnce(
             &DlcserviceClientImpl::OnInstall, weak_ptr_factory_.GetWeakPtr(),
             dlc_id, std::move(install_callback), std::move(progress_callback)));