Fix some feedback UI polish.

chrome/browser/resources/feedback/css/feedback.css

 /* Copyright 2013 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 {
   height: 100%;
 }
 
 body {
+  background-color: #fbfbfb;
   height: 100%;
   margin: 0;
   padding: 0;
   width: 100%;
 }
 
 .title-bar {
   -webkit-align-items: center;
+  -webkit-app-region: drag;
   background-color: #fff;
   box-shadow: 0 1px #d0d0d0;
   color: rgb(80, 80, 82);
   display: -webkit-flex;
   font-size: 15px;
   height: 48px;
 }
 
 .title-bar #page-title {
-  -webkit-app-region: drag;
   -webkit-flex: 1 1 auto;
   -webkit-margin-start: 20px;
 }
 
 .title-bar .button-bar {
   -webkit-flex: 0 1 auto;
 }
 
 .content {
-  background-color: #fbfbfb;
   color: #646464;
   font-size: 12px;
   margin: 20px;
 }
 
 .content #description-text {
   border-color: #c8c8c8;
   box-sizing: border-box;
   height: 120px;
   line-height: 18px;
@@ skipping 79 matching lines @@
 
 button.white-button {
   -webkit-margin-end: 10px;
   color: #000;
 }
 
 button.blue-button {
   color: #fff;
   text-shadow: 1px sharp drop shadow rgb(45, 106, 218);
 }