Sets up infrastructure to migrate extensions of type 'view'

This adds the basic infrastucture needed to start migrating 'view' extensions from the module.json system to a JavaScript declaration based system. As more views are migrated the infrastructure may be further modified.

Bug:1134103
Change-Id: I8ba4609ee9e1899cbd679624a49a7b16e8120140
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2508282
Commit-Queue: Andres Olivares <andoli@chromium.org>
Reviewed-by: Tim van der Lippe <tvanderlippe@chromium.org>
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 5f58cf5..0b0ad23 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -158,8 +158,9 @@
         args = ['--autofix', '--all']
     else:
         devtools_front_end = input_api.os_path.join(devtools_root, 'front_end')
-        affected_front_end_files = _getAffectedFiles(input_api, [devtools_front_end], ['D'],
-                                                     ['.js', '.grdp', '.grd', 'module.json'])
+        affected_front_end_files = _getAffectedFiles(
+            input_api, [devtools_front_end], ['D'],
+            ['.ts', '.js', '.grdp', '.grd', 'module.json'])
 
         if len(affected_front_end_files) == 0:
             return [