Remove renderer process CefURLRequest support

The CefFrame::CreateURLRequest method is no longer supported in the renderer
process. Usage of this method was already limited to same-origin requests due
to renderer process CORS restrictions, and the underlying Blink API has now
been removed in https://crbug.com/1413912 (M112+).

Existing alternatives include CefURLRequest usage in the browser process, or
JavaScript XMLHttpRequest/fetch API usage in the renderer process.

patch/patch.cfg

@@ -471,11 +471,6 @@ patches = [
     # http://crrev.com/3955c9f9eb
     'name': 'set_resize_background_color',
   },
-  {
-    # Restore WebUrlLoader Cancel method.
-    # https://chromium-review.googlesource.com/c/chromium/src/+/1617042
-    'name': 'web_url_loader_cancel_1617042',
-  },
   {
     # Avoid a shutdown crash with multi-threaded message loop caused by
     # |g_browser_task_executor->browser_ui_thread_scheduler_| being null when

patch/patches/web_url_loader_cancel_1617042.patch

@@ -1,21 +0,0 @@
-diff --git third_party/blink/public/platform/web_url_loader.h third_party/blink/public/platform/web_url_loader.h
-index 31054cf2795a4..d5082be28ea54 100644
---- third_party/blink/public/platform/web_url_loader.h
-+++ third_party/blink/public/platform/web_url_loader.h
-@@ -143,12 +143,14 @@ class BLINK_PLATFORM_EXPORT WebURLLoader {
-   void SetResourceRequestSenderForTesting(
-       std::unique_ptr<WebResourceRequestSender> resource_request_sender);
- 
-+  // Cancels an asynchronous load.  This will appear as a load error to
-+  // the client.
-+  void Cancel();
-+
-  private:
-   class Context;
-   class RequestPeerImpl;
- 
--  void Cancel();
--
-   scoped_refptr<Context> context_;
- };
-