Material PDF: Fix inconsistent behaviour in page selector, update styling

chrome/browser/resources/pdf/elements/viewer-pdf-toolbar/viewer-pdf-toolbar.css

 /* Copyright 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. */
 
 /* We introduce a wrapper animatable element and set the overflow since
  * core-transition interferes with the box-shadow from paper-shadow. */
 #animatable {
   overflow: visible;
 }
 
 /* We introduce a wrapper aligner element as setting the relevant attributes
  * (horizontal justified layout center) have no effect on the core-toolbar. */
 #aligner {
   width: 100%;
 }
 
 #title {
+  /* paper-toolbar enforces a layout on anything with a title attribute which
+   * sets `flex: 1`. We must overwrite it here rather than with the 'flex-5'
+   * class.
+   * TODO(tsergeant): Remove this once it is fixed from the Polymer side.
+   */
+  flex: 5;
   overflow: hidden;
   text-overflow: ellipsis;
   white-space: nowrap;
 }
 
 #pageselector-container {
   text-align: center;
   /* The container resizes according to the width of the toolbar. On small
    * screens with large numbers of pages, overflow page numbers without
    * wrapping. */
   white-space: nowrap;
 }
 
 #buttons {
   text-align: right;
 }
 
+#buttons > paper-icon-button {
+  margin-right: 0;
+}
+
 paper-progress {
   height: 56px;
   position: absolute;
   width: 100%;
   z-index: 3;
 }
 
 paper-progress::shadow #activeProgress {
-  background-color: rgb(27, 168, 243);
+  background-color: rgb(50, 54, 57);
 }
 
 paper-progress::shadow #progressContainer {
-  background-color: rgb(100, 181, 246);
+  background-color: rgba(0, 0, 0, 0.3);
 }
 
 paper-toolbar {
-  background-color: rgb(27, 168, 243);
+  background-color: rgb(50, 54, 57);
   color: rgb(241, 241, 241);
   font-size: 1.5em;
   height: 56px;
   padding-left: 1em;
   padding-right: 1em;
   z-index: 3;
 }
 
 paper-toolbar /deep/ ::selection {
-  background: rgb(187, 222, 251);
+  background: rgba(255, 255, 255, 0.3);
 }
 
 paper-toolbar /deep/ .toolbar-tools {
   height: 56px;
 }
 
 .invisible {
   visibility: hidden;
 }