Improve UI for unpacked extensions failing to load

chrome/browser/resources/extensions/extension_load_error.css

+/* Copyright 2014 The Chromium Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file. */
+
+#extension-load-error {
+  -webkit-margin-before: 10px;
+  -webkit-margin-end: 20px;
+  -webkit-padding-after: 10px;
+  -webkit-padding-end: 3px;
+  -webkit-padding-start: 10px;
+  background-color: rgba(255, 249, 221, 1);
+  border-radius: 7px;
+  display: flex;
+  flex-direction: column;
+  font-size: 1.1em;
+}
+
+#extension-load-error h2 {
+  font-size: 14px;
+  font-weight: bold;
+}
+
+#extension-load-error-message {
+  -webkit-margin-before: 5px;
+}
+
+#extension-load-error-manifest {
+  -webkit-margin-after: 10px;
+  -webkit-margin-before: 10px;
+  background-color: rgba(255, 250, 240, 1);
+  max-height: 100px;
+}
+
+#extension-load-error-manifest .extension-code-highlighted-source {
+  background-color: pink;
+}
+
+#extension-load-error-controls {
+  align-self: flex-end;
+}