android: Retry detached requests on network change.

Some detached requests fail because the network changes between
requests. Retry the request in this case, only once.

Bug: 851399
Change-Id: Ic77c28e5ac49fecaf634e4a225c8f443f75e2560
Reviewed-on: https://chromium-review.googlesource.com/1118262Reviewed-by: Michael van Ouwerkerk <mvanouwerkerk@chromium.org>
Commit-Queue: Benoit L <lizeb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#571173}

chrome/browser/android/customtabs/detached_resource_request.cc

@@ -106,6 +106,10 @@ void DetachedResourceRequest::Start(
   request->url_loader_->SetOnRedirectCallback(
       base::BindRepeating(&DetachedResourceRequest::OnRedirectCallback,
                           base::Unretained(request.get())));
+  // Only retry on network changes, not HTTP 5xx codes. This is a client-side
+  // failure, and main requests are retried in this case.
+  request->url_loader_->SetRetryOptions(
+      1 /* max_retries */, network::SimpleURLLoader::RETRY_ON_NETWORK_CHANGE);
 
   // |url_loader_| is owned by the request, and must be kept alive to not cancel
   // the request. Pass the ownership of the request to the response callback,