Shorten package names in dependency visualization

The shortener is Chrome-specific. It replaces:
"org.chromium.chrome.browser.foo" with ".c.b.foo"

Also git ignore json_graph.txt

Bug: 1093962
Change-Id: Id1d84f7b2478672c7db6ef6370bb86654687cdc7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2254096
Commit-Queue: Henrique Nakashima <hnakashima@chromium.org>
Reviewed-by: Samuel Huang <huangs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#780908}

tools/android/dependency_analysis/js/.gitignore

 node_modules/
+json_graph.txt
 package-lock.json

tools/android/dependency_analysis/js/chrome_hooks.js

+// Copyright 2020 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.
+
+/**
+ * Shortens a package name to be displayed in the svg.
+ * @param {string} name The full package name to shorten.
+ * @return {string} The shortened package name.
+ */
+function shortenPackageName(name) {
+  return name
+      .replace('org.chromium.', '.')
+      .replace('chrome.browser.', 'c.b.');
+}
+
+export {
+  shortenPackageName,
+};

tools/android/dependency_analysis/js/process_graph_json.js

@@ -3,14 +3,7 @@
 // found in the LICENSE file.
 
 import {Node, Edge, Graph} from './graph_model.js';
-
-/**
- * TODO(yjlong): Compute the "shortest disambiguated name" in Python and include
- * it in the JSON so we do not need to do this calculation.
- * @param {number} name The full package name to shorten.
- * @return {number} The shortened package name.
- */
-const shortName = name => name.substring(name.lastIndexOf('.') + 1);
+import {shortenPackageName} from './chrome_hooks.js';
 
 /**
  * A graph read from JSON.
@@ -28,7 +21,7 @@ const shortName = name => name.substring(name.lastIndexOf('.') + 1);
 function parseGraphFromJson(jsonGraph) {
   const graph = new Graph();
   for (const nodeData of jsonGraph.nodes) {
-    const node = new Node(nodeData.name, shortName(nodeData.name));
+    const node = new Node(nodeData.name, shortenPackageName(nodeData.name));
     graph.addNodeIfNew(node);
   }
   for (const edgeData of jsonGraph.edges) {