RC: First cut graph animation.

This shows a continuously updating graph of pages, frames and processes.

Bug: 891310
Change-Id: I1b2f462740374dfb1d2529057d1831dc240e79f2
Reviewed-on: https://chromium-review.googlesource.com/c/1313449Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Reviewed-by: Chris Hamilton <chrisha@chromium.org>
Commit-Queue: Sigurður Ásgeirsson <siggi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605674}

chrome/browser/resources/discards/graph_doc_template.html

@@ -28,6 +28,10 @@ URL. As result, this document needs to be self-contained, hence inline scripts.
         stroke-width: 1.5px;
       }
     </style>
+  <script src="https://ajax.googleapis.com/ajax/libs/d3js/5.7.0/d3.min.js"
+      integrity="sha384-HL96dun1KbYEq6UT/ZlsspAODCyQ+Zp4z318ajUPBPSMzy5dvxl6ziwmnil8/Cpd"
+      crossorigin="anonymous">
+  </script>
   <script type="application/javascript">
 ${javascript_file}
   </script>