Add support for PDFium to my_activity.py

Change-Id: I0febf1c3442511b8c82129c82cf9c68f7c37329c
Reviewed-on: https://chromium-review.googlesource.com/671548
Reviewed-by: Marc-Antoine Ruel <maruel@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>

my_activity.py

@@ -107,6 +107,9 @@ gerrit_instances = [
   {
     'url': 'android-review.googlesource.com',
   },
+  {
+    'url': 'pdfium-review.googlesource.com',
+  },
 ]
 
 google_code_projects = [
@@ -124,6 +127,11 @@ google_code_projects = [
   {
     'name': 'skia',
   },
+  {
+    'name': 'pdfium',
+    'shorturl': 'crbug.com/pdfium',
+    'short_url_protocol': 'https',
+  },
 ]
 
 def username(email):