[Nearby] Formatting changes for the Nearby Share debug page.

Updated the font and fixed a double border problem on the Contacts Tab
and the HTTP Messages tab. Font screenshot here:
https://screenshot.googleplex.com/8a9a5ca4-623f-4b51-8e79-70da2e23f478

Change-Id: Id202125317b50ee07dd514587f51a785cbd622f9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2363714
Commit-Queue: Juliet Levesque <julietlevesque@google.com>
Reviewed-by: Josh Nohle <nohle@chromium.org>
Cr-Commit-Position: refs/heads/master@{#799512}

chrome/browser/resources/nearby_internals/contact_tab.html

@@ -3,10 +3,6 @@
     --standard-border: 1px solid black;
   }
 
-  #contact-list:last-child {
-    border-bottom: var(--standard-border);
-  }
-
   #clearButton {
     float: right;
   }
@@ -22,10 +18,10 @@
     id="clearButton" disabled="[[!contactList_.length]]">
  Clear Messages
 </cr-button>
-<iron-list items="[[contactList_]]" as="contact" id="contact-list"
+<doom-repeat items="[[contactList_]]" as="contact" id="contact-list"
     hidden="[[!contactList_.length]]">
   <template>
     <contact-object item="[[contact]]">
     </contact-object>
   </template>
-</iron-list>
+</dom-repeat>

chrome/browser/resources/nearby_internals/http_message_object.html

-<style>
+<style include="shared-style">
   :host {
     --standard-border: 1px solid black;
   }
 
   #item {
-    border: var(--standard-border);
+    border-left: var(--standard-border);
+    border-right: var(--standard-border);
+    border-top: var(--standard-border);
   }
 
   #header {

chrome/browser/resources/nearby_internals/http_tab.html

@@ -20,7 +20,6 @@
     id="clearButton" disabled="[[!httpMessageList_.length]]">
  Clear Messages
 </cr-button>
-
 <dom-repeat items="[[httpMessageList_]]" as="http-message"
     hidden="[[!httpMessageList_.length]]">
   <template>

chrome/browser/resources/nearby_internals/shared_style.html

@@ -2,12 +2,14 @@
   <style include="cr-shared-style">
     :host {
       cursor: default;
-      font-family: Roboto, Roboto, sans-serif;
+      font-family: monospace;
+      font-size: 12px;
     }
 
     .internals-button {
       background-color: rgb(0, 134, 179);
       color: white;
+      font-family: Roboto;
       margin: 5px;
     }
   </style>