Reland of [Payments] move //components/payments/content/*.mojom files to //components/payments/mojom

components/payments/mojom/BUILD.gn

Index: components/payments/mojom/BUILD.gn
diff --git a/components/payments/mojom/BUILD.gn b/components/payments/mojom/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..9268a078a11a9f4c7a8d2ce530b9990183768c8d
--- /dev/null
+++ b/components/payments/mojom/BUILD.gn
@@ -0,0 +1,33 @@
+# Copyright 2017 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.
+
+import("//mojo/public/tools/bindings/mojom.gni")
+
+mojom("mojom") {
+  sources = [
+    "payment_request.mojom",
+  ]
+}
+
+mojom("mojom_parser") {
+  sources = [
+    "payment_manifest_parser.mojom",
+  ]
+
+  public_deps = [
+    "//url/mojo:url_mojom_gurl",
+  ]
+}
+
+mojom("mojom_payment_app") {
+  sources = [
+    "payment_app.mojom",
+  ]
+
+  public_deps = [
+    ":mojom",
+    "//mojo/common:common_custom_types",
+    "//url/mojo:url_mojom_gurl",
+  ]
+}