Bring back the URLLoader from the old Mandoline network service.

content/network/DEPS

Index: content/network/DEPS
diff --git a/content/network/DEPS b/content/network/DEPS
index 5860594df54dcffdd01a539dd877d2a820cd816d..b049baaea1743e533c6cab70539b9d388535d3d7 100644
--- a/content/network/DEPS
+++ b/content/network/DEPS
@@ -1,3 +1,19 @@
+# Tight rules since this will move to services/network. See README.
 include_rules = [
+  "-content",
+  "+content/common/content_export.h",
+  "+content/common/url_loader.mojom.h",
+  "+content/common/url_loader_factory.mojom.h",
+  "+content/network",
+  "+content/public/common/content_client.h",
+  "+content/public/common/referrer.h",
+  "+content/public/common/resource_response.h",
   "+services/service_manager/public",
 ]
+
+specific_include_rules = {
+  '.*_[a-z]*test.*': [
+    "+content/browser/loader/test_url_loader_client.h",
+    "+content/public/common/content_paths.h",
+  ],
+}