Drop generic linkifier from linkify-branch-refs

Closes #2275
Partial solution to #1985

source/features/linkify-branch-refs.tsx

@@ -1,53 +1,10 @@
 import React from 'dom-chef';
-import select from 'select-dom';
 import elementReady from 'element-ready';
 import features from '../libs/features';
-import * as pageDetect from '../libs/page-detect';
 import {getOwnerAndRepo} from '../libs/utils';
 import {wrap} from '../libs/dom-utils';
 
-function inPR(): void {
-	let deletedBranch: string | undefined;
-	const lastBranchAction = select.all(`
-		.discussion-item-head_ref_deleted .commit-ref,
-		.discussion-item-head_ref_restored .commit-ref
-	`).pop();
-	if (lastBranchAction && lastBranchAction.closest('.discussion-item-head_ref_deleted')) {
-		deletedBranch = lastBranchAction.textContent!.trim();
-	}
-
-	// Find the URLs first, some elements don't have titles
-	const urls = new Map<string, string>();
-	for (const el of select.all('.commit-ref[title], .base-ref[title], .head-ref[title]')) {
-		const [repo, branch] = el.title.split(':');
-		const branchName = el.textContent!.trim();
-		urls.set(
-			branchName,
-			`/${repo}`
-		);
-		if (branchName !== deletedBranch) {
-			urls.set(
-				branchName,
-				`/${repo}/tree/${encodeURIComponent(branch)}`
-			);
-		}
-	}
-
-	for (const el of select.all('.commit-ref')) {
-		const branchName = el.textContent!.trim();
-
-		if (branchName !== 'unknown repository') {
-			if (branchName === deletedBranch) {
-				el.title = 'Deleted';
-				el.style.textDecoration = 'line-through';
-			}
-
-			wrap(el, <a href={urls.get(branchName)}></a>);
-		}
-	}
-}
-
-async function inQuickPR(): Promise<void> {
+async function init(): Promise<void> {
 	const el = await elementReady('.branch-name');
 	if (el) {
 		const {ownerName, repoName} = getOwnerAndRepo();
@@ -56,19 +13,10 @@ async function inQuickPR(): Promise<void> {
 	}
 }
 
-function init(): void {
-	if (pageDetect.isPR()) {
-		inPR();
-	} else if (pageDetect.isQuickPR()) {
-		inQuickPR();
-	}
-}
-
 features.add({
 	id: __featureName__,
 	description: 'Click on branch references in pull requests',
 	include: [
-		features.isPR,
 		features.isQuickPR
 	],
 	load: features.onAjaxedPages,