chore: remove obsolete webview patch (#23341)

https://chromium-review.googlesource.com/c/chromium/src/+/2135187
has been landed in upstream.

patches/chromium/.patches

@@ -86,7 +86,6 @@ delay_lock_the_protocol_scheme_registry.patch
 gpu_notify_when_dxdiag_request_fails.patch
 feat_allow_embedders_to_add_observers_on_created_hunspell.patch
 feat_add_onclose_to_messageport.patch
-fix_undo_redo_broken_in_webviews.patch
 fix_account_for_print_preview_disabled_when_printing_to_pdf.patch
 web_contents.patch
 ui_gtk_public_header.patch

patches/chromium/fix_undo_redo_broken_in_webviews.patch

@@ -1,36 +0,0 @@
-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Shelley Vohr <[email protected]>
-Date: Tue, 31 Mar 2020 14:32:33 -0700
-Subject: fix: undo redo broken in webviews
-
-When propagating the undo and redo events from the menu, Chromium was not
-properly sending the events to the focused webcontents on macOS. This fixes
-that error. A crbug has been opened at https://bugs.chromium.org/p/chromium/issues/detail?id=1067284
-and this patch will be removed when it has been resolved upstream.
-
-diff --git a/content/browser/renderer_host/render_widget_host_view_mac.mm b/content/browser/renderer_host/render_widget_host_view_mac.mm
-index 9fe6d55cc0dbcc504cdf0eebe71899887de31b19..ef464a68a9925ecef869415ed8ba1c361448b93f 100644
---- a/content/browser/renderer_host/render_widget_host_view_mac.mm
-+++ b/content/browser/renderer_host/render_widget_host_view_mac.mm
-@@ -38,6 +38,7 @@
- #include "content/browser/renderer_host/render_widget_host_input_event_router.h"
- #import "content/browser/renderer_host/text_input_client_mac.h"
- #import "content/browser/renderer_host/ui_events_helper.h"
-+#include "content/browser/web_contents/web_contents_impl.h"
- #include "content/common/text_input_state.h"
- #include "content/common/view_messages.h"
- #include "content/public/browser/browser_context.h"
-@@ -978,7 +979,12 @@ gfx::Range RenderWidgetHostViewMac::ConvertCharacterRangeToCompositionRange(
- }
- 
- WebContents* RenderWidgetHostViewMac::GetWebContents() {
--  return WebContents::FromRenderViewHost(RenderViewHost::From(host()));
-+  auto* wc = WebContents::FromRenderViewHost(RenderViewHost::From(host()));
-+  if (wc) {
-+    WebContentsImpl* web_contents_impl = static_cast<WebContentsImpl*>(wc);
-+    return web_contents_impl->GetFocusedWebContents();
-+  }
-+  return wc;
- }
- 
- bool RenderWidgetHostViewMac::GetCachedFirstRectForCharacterRange(