Introduce SystemNetworkContextManager.

content/public/test/test_url_loader_client.h

Index: content/public/test/test_url_loader_client.h
diff --git a/content/browser/loader/test_url_loader_client.h b/content/public/test/test_url_loader_client.h
similarity index 98%
rename from content/browser/loader/test_url_loader_client.h
rename to content/public/test/test_url_loader_client.h
index bb5e249a5ef58ced5bd27b453824171f3714705f..7d7bb9f9dcf368a325e11f3176254b926451474e 100644
--- a/content/browser/loader/test_url_loader_client.h
+++ b/content/public/test/test_url_loader_client.h
@@ -57,9 +57,7 @@ class TestURLLoaderClient final : public mojom::URLLoaderClient {
   const ResourceResponseHead& response_head() const { return response_head_; }
   const base::Optional<net::SSLInfo>& ssl_info() const { return ssl_info_; }
   const net::RedirectInfo& redirect_info() const { return redirect_info_; }
-  const std::string& cached_metadata() const {
-    return cached_metadata_;
-  }
+  const std::string& cached_metadata() const { return cached_metadata_; }
   mojo::DataPipeConsumerHandle response_body() { return response_body_.get(); }
   mojo::ScopedDataPipeConsumerHandle response_body_release() {
     return std::move(response_body_);