Get screen-sharing working, somehow

Signed-off-by: Šimon Brandner <simon.bra.ag@gmail.com>

res/css/views/elements/_DesktopCapturerSourcePicker.scss

@@ -0,0 +1,73 @@
+/*
+Copyright 2015, 2016 OpenMarket Ltd
+Copyright 2019 Michael Telatynski <7t3chguy@gmail.com>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+.mx_streamSelectorDialog {
+    -ms-text-overflow: ellipsis;
+    text-overflow: ellipsis;
+    white-space: nowrap;
+    overflow: hidden;
+    margin: 0 auto;
+    padding-right: 80px;
+}
+.desktop-capturer-selection-scroller {
+    width: 100%;
+    max-height: 100vh;
+    overflow-y: auto;
+}
+.desktop-capturer-selection-list {
+    max-width: calc(100% - 100px);
+    margin: 0 50px 0 50px;
+    padding: 0;
+    display: flex;
+    flex-wrap: wrap;
+    list-style: none;
+    overflow: hidden;
+    justify-content: center;
+}
+.desktop-capturer-selection-item {
+    display: flex;
+    margin: 4px;
+}
+.desktop-capturer-selection-button {
+    display: flex;
+    flex-direction: column;
+    align-items: stretch;
+    width: 145px;
+    margin: 0;
+    border: 0;
+    border-radius: 4px;
+    padding: 4px;
+    background: #20262b;
+    color: #ffffff;
+    text-align: left;
+    transition: background-color .15s, box-shadow .15s;
+}
+.desktop-capturer-selection-button:hover,
+.desktop-capturer-selection-button:focus {
+    background: #363c43;
+}
+.desktop-capturer-selection-thumbnail {
+    width: 100%;
+    height: 81px;
+    object-fit: cover;
+}
+.desktop-capturer-selection-name {
+    margin: 6px 0 6px;
+    white-space: nowrap;
+    text-overflow: ellipsis;
+    overflow: hidden;
+}