DevTools: Use TextPrompt for FilterBar instead of input element

third_party/WebKit/Source/devtools/front_end/ui/textPrompt.css

 /*
  * Copyright (c) 2015 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.
  */
 
 .text-prompt-editing {
     -webkit-user-select: text;
     box-shadow: 0 0 0 1px rgba(0, 0, 0, 0.2),
                 0 2px 4px rgba(0, 0, 0, 0.2),
@@ skipping 11 matching lines @@
 }
 
 .text-prompt-editing,
 .text-prompt-editing ::content * {
     color: #222 !important;
     text-decoration: none !important;
     -webkit-user-modify: read-write-plaintext-only;
     white-space: pre;
 }
 
-::content .auto-complete-text,
-.text-prompt-editing ::content .auto-complete-text {
+::content .auto-complete-text {
     color: rgb(128, 128, 128) !important;
     -webkit-user-select: none;
     -webkit-user-modify: read-only;
 }
 
+::content .text-prompt:empty::before {
+    content: attr(data-placeholder);
+    color: rgb(128, 128, 128);
+}
+
 .text-prompt-editing ::content br {
     display: none;
 }