Remove patches/chrome-browser-net-net_error_tab_helper.cc.patch

Description

The purpose of this patch is to disable DNS probing whenever a page fails to load with a DNS-related error, which seems to be the main reason for NetErrorTabHelper existence. The other use of an instance of this class is from chrome/browser/offline_pages/offline_page_utils.cc, where it’s retrieved from the WebContents to determine whether a download button should be shown from an error page:

bool OfflinePageUtils::IsShowingDownloadButtonInErrorPage(
    content::WebContents* web_contents) {
  chrome_browser_net::NetErrorTabHelper* tab_helper =
      chrome_browser_net::NetErrorTabHelper::FromWebContents(web_contents);
  return tab_helper && tab_helper->is_showing_download_button_in_error_page();
}

However, this relies on NetErrorTabHelper::is_showing_download_button_in_error_page(), which is only defined if chromium is built with enable_offline_pages = true, which is not the case for Brave.

Therefore, it should be possible to drop this patch by simply avoiding the instantiation of NetErrorTabHelper and getting it added to the relevant WebContents in the first place.

Desktop Brave version:

Brave 1.22.28 (Chromium 89.0.4389.48)

Miscellaneous Information:

For QA purposes: this cleanup touched code added to fix bug https://github.com/brave/brave-browser/issues/3249, so please make sure behaviour remains the same (there’s a test plan specified in that issue).

[jumde]

that’s good!

[mariospr]

@mariospr looks like the issue you referenced, #3249, is only a Windows issue. Is it appropriate to change this issue from Android/Desktop to Windows only?

Yes, sorry for the confusion (it was my fault for not properly setting the tags). Please do move it to Windows-only, thanks!