Update missing/downloading/blocked/unsupported/disabled plugin UI.

chrome/renderer/resources/plugins/plugin_placeholders.css

 /* Copyright (c) 2012 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. */
 
 html, body {
   -webkit-user-select: none;
   font-family: sans-serif;
   height: 100%;
   margin: 0;
   overflow: hidden;
   text-align: center;
   width: 100%;
 }
 
 h1 {
+  display: none;
   font-size: 10pt;
   font-weight: normal;
   padding: 0pt 10pt;
-<if expr="not is_android and not chromeos">
-  visibility: hidden;
-</if>
-}
-
-#outer:hover h1, #outer:hover #close {
-  visibility: visible;
 }
 
 p {
   font-size: 8pt;
   padding: 0pt 14pt;
 }
 
 #outer {
   align-items: center;
-  border: 1px black solid;
   box-sizing: border-box;
   display: flex;
   height: 100%;
   justify-content: center;
   position: absolute;
   width: 100%;
+  flex-direction: column;
 }
 
-#close {
-  background-image: -webkit-image-set(
-      url(../../../../ui/resources/default_100_percent/close_2.png) 1x,
-      url(../../../../ui/resources/default_200_percent/close_2.png) 2x);
-  background-position: right top;
-  background-repeat: no-repeat;
-  cursor: pointer;
-  height: 14px;
-  position: absolute;
-  right: 3px;
-  top: 3px;
-<if expr="not is_android">
-  visibility: hidden;
-</if>
-  width: 14px;
+.icon {
+  max-height: 100%;
+  max-width: 100%;
 }
 
-#close[data-plugin-type='document'] {
-  display: none;
+@media (orientation: landscape) and (min-height: 2em) and (min-width: 14em) {
+  #outer {
+    flex-direction: row;
+  }
+  .icon {
+    max-height: 100%;
+    max-width: 50%;
+  }
+  h1 {
+    display: block;
+  }
 }
 
-#close:hover {
-  background-image: -webkit-image-set(
-      url(../../../../ui/resources/default_100_percent/close_2_hover.png) 1x,
-      url(../../../../ui/resources/default_200_percent/close_2_hover.png) 2x);
+@media (min-height: 7em) and (min-width: 6em) {
+  #outer {
+    flex-direction: column;
+  }
+  .icon {
+    max-height: 50%;
+    max-width: 100%;
+  }
+  h1 {
+    display: block;
+  }
 }
-
-#close:active {
-  background-image: -webkit-image-set(
-      url(../../../../ui/resources/default_100_percent/close_2_pressed.png) 1x,
-      url(../../../../ui/resources/default_200_percent/close_2_pressed.png) 2x);
-}