<!--  As an open source project with a dedicated but small maintainer team, it can sometimes take a long time for issues to be addressed so please be patient and we will get back to you as soon as we can.
-->

### Preflight Checklist
<!-- Please ensure you've completed the following steps by replacing [ ] with [x]-->

* [x] I have read the [Contributing Guidelines](https://github.com/electron/electron/blob/master/CONTRIBUTING.md) for this project.
* [x] I agree to follow the [Code of Conduct](https://github.com/electron/electron/blob/master/CODE_OF_CONDUCT.md) that this project adheres to.
* [x] I have searched the issue tracker for an issue that matches the one I want to file, without success.

### Issue Details

* **Electron Version:**
  * 7.0.0
* **Operating System:**
  * Windows 10 (1803)
* **Last Known Working Electron version:**
  * 6.1.2

### Expected Behavior
Loading flash content through an swf file results in the correct visualization of said content

### Actual Behavior
An error "GET http://interactive-mirror3.nfb.ca/FrameLoader.swf net::ERR_INVALID_ARGUMENT" appears:

![Annotazione 2019-10-25 170420](https://user-images.githubusercontent.com/6009920/67582177-8a829e00-f749-11e9-8e0d-1d08c4930084.png)


### To Reproduce
Try embedding this flash website in an electron project (http://bear71.nfb.ca/#/bear71) following this tutorial: https://electronjs.org/docs/tutorial/using-pepper-flash-plugin

<!--
For bugs that can be encapsulated in a small experiment, you can use Electron Fiddle (https://github.com/electron/fiddle) to publish your example to a GitHub Gist and link it your bug report.
-->

<!--
If Fiddle is insufficient to produce an example, please provide an example REPOSITORY that can be cloned and run. You can fork electron-quick-start (https://github.com/electron/electron-quick-start) and include a link to the branch with your changes.
-->

<!--
If you provide a URL, please list the commands required to clone/setup/run your repo e.g.
```sh
$ git clone $YOUR_URL -b $BRANCH
$ npm install
$ npm start || electron .
```
-->

### Screenshots
![Annotazione 2019-10-25 170420](https://user-images.githubusercontent.com/6009920/67582177-8a829e00-f749-11e9-8e0d-1d08c4930084.png)

### Additional Information
<!-- Add any other context about the problem here. -->

shell/browser/net/system_network_context_manager.cc
#include "shell/browser/net/system_network_context_manager.h"
#include <string>
#include <utility>
#include "base/command_line.h"
#include "chrome/browser/browser_process.h"
#include "chrome/browser/net/chrome_mojo_proxy_resolver_factory.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/network_service_instance.h"
#include "content/public/common/content_features.h"
#include "content/public/common/service_names.mojom.h"
#include "mojo/public/cpp/bindings/associated_interface_ptr.h"
#include "mojo/public/cpp/bindings/pending_receiver.h"
#include "net/net_buildflags.h"
#include "services/network/network_service.h"
#include "services/network/public/cpp/cross_thread_pending_shared_url_loader_factory.h"
#include "services/network/public/cpp/features.h"
#include "services/network/public/cpp/shared_url_loader_factory.h"
#include "shell/browser/electron_browser_client.h"
#include "shell/common/application_info.h"
#include "shell/common/options_switches.h"
#include "url/gurl.h"
namespace {
SystemNetworkContextManager* g_system_network_context_manager = nullptr;
network::mojom::HttpAuthStaticParamsPtr CreateHttpAuthStaticParams() {