Use web-app manifest format for Android payment apps.

components/payments/content/payment_manifest_downloader.cc

Index: components/payments/content/payment_manifest_downloader.cc
diff --git a/components/payments/content/payment_manifest_downloader.cc b/components/payments/content/payment_manifest_downloader.cc
index 799769f533683969b352502e065a782265274523..ddce8c77192d0205c22727d7c57f3a3d331fe529 100644
--- a/components/payments/content/payment_manifest_downloader.cc
+++ b/components/payments/content/payment_manifest_downloader.cc
@@ -42,10 +42,18 @@ PaymentManifestDownloader::PaymentManifestDownloader(
 
 PaymentManifestDownloader::~PaymentManifestDownloader() {}
 
-void PaymentManifestDownloader::Download() {
+void PaymentManifestDownloader::DownloadPaymentMethodManifest() {
+  DCHECK(!fetcher_);
+  is_downloading_http_link_header_ = true;
   InitiateDownload(method_name_, net::URLFetcher::HEAD);
 }
 
+void PaymentManifestDownloader::DownloadWebAppManifest() {
+  DCHECK(!fetcher_);
+  is_downloading_http_link_header_ = false;
+  InitiateDownload(method_name_, net::URLFetcher::GET);
+}
+
 void PaymentManifestDownloader::InitiateDownload(
     const GURL& url,
     net::URLFetcher::RequestType request_type) {