Bug 1771487 - Ensure iframes in the screenshots UI are transparent after bug 1738380. r=Gijs

While at it, also ensure they have standards mode and utf-8 charset. Differential Revision: https://phabricator.services.mozilla.com/D147513
2022-05-30 14:56:06 +00:00 · 2022-05-30 14:56:06 +00:00 · b32cc07363
--- a/browser/extensions/screenshots/blank.html
+++ b/browser/extensions/screenshots/blank.html
@ -1,5 +1,8 @@
+<!doctype html>
+
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
   - License, v. 2.0. If a copy of the MPL was not distributed with this file,
   - You can obtain one at http://mozilla.org/MPL/2.0/. -->

-<html></html>
+<meta charset="utf-8">
+<meta name="color-scheme" content="light dark">
--- a/browser/extensions/screenshots/selector/ui.js
+++ b/browser/extensions/screenshots/selector/ui.js
@ -101,6 +101,7 @@ this.ui = (function() {
              // eslint-disable-next-line no-unsanitized/property
              this.document.documentElement.innerHTML = `
               <head>
+                <meta name="color-scheme" content="light dark">
                <style>${substitutedCss}</style>
                <title></title>
               </head>
@ -255,6 +256,7 @@ this.ui = (function() {
              this.document.documentElement.innerHTML = `
               <head>
                <link rel="localization" href="browser/screenshots.ftl">
+                <meta name="color-scheme" content="light dark">
                <style>${substitutedCss}</style>
                <title></title>
               </head>
@ -397,6 +399,7 @@ this.ui = (function() {
              this.document.documentElement.innerHTML = `
                <head>
                  <link rel="localization" href="browser/screenshots.ftl">
+                  <meta name="color-scheme" content="light dark">
                  <style>${substitutedCss}</style>
                  <title></title>
                </head>