The dependency script wasn't catching quite all our transitive dependencies (#13954)

diff --git a/examples/flutter_gallery/pubspec.yaml b/examples/flutter_gallery/pubspec.yaml
index 081b6ea..201d6cc 100644
--- a/examples/flutter_gallery/pubspec.yaml
+++ b/examples/flutter_gallery/pubspec.yaml
@@ -28,16 +28,21 @@
   barback: 0.15.2+13 # TRANSITIVE DEPENDENCY
   boolean_selector: 1.0.2 # TRANSITIVE DEPENDENCY
   charcode: 1.1.1 # TRANSITIVE DEPENDENCY
+  cli_util: 0.1.2+1 # TRANSITIVE DEPENDENCY
   convert: 2.0.1 # TRANSITIVE DEPENDENCY
   crypto: 2.0.2+1 # TRANSITIVE DEPENDENCY
+  csslib: 0.14.1 # TRANSITIVE DEPENDENCY
   file: 2.3.5 # TRANSITIVE DEPENDENCY
   glob: 1.1.5 # TRANSITIVE DEPENDENCY
+  html: 0.13.2+1 # TRANSITIVE DEPENDENCY
   http: 0.11.3+14 # TRANSITIVE DEPENDENCY
   http_multi_server: 2.0.4 # TRANSITIVE DEPENDENCY
   http_parser: 3.1.1 # TRANSITIVE DEPENDENCY
   io: 0.3.1 # TRANSITIVE DEPENDENCY
+  isolate: 1.1.0 # TRANSITIVE DEPENDENCY
   js: 0.6.1 # TRANSITIVE DEPENDENCY
   json_rpc_2: 2.0.5 # TRANSITIVE DEPENDENCY
+  logging: 0.11.3+1 # TRANSITIVE DEPENDENCY
   matcher: 0.12.1+4 # TRANSITIVE DEPENDENCY
   meta: 1.1.1 # TRANSITIVE DEPENDENCY
   mime: 0.9.5 # TRANSITIVE DEPENDENCY
@@ -46,6 +51,7 @@
   package_config: 1.0.3 # TRANSITIVE DEPENDENCY
   package_resolver: 1.0.2 # TRANSITIVE DEPENDENCY
   path: 1.5.1 # TRANSITIVE DEPENDENCY
+  plugin: 0.2.0+2 # TRANSITIVE DEPENDENCY
   pool: 1.3.4 # TRANSITIVE DEPENDENCY
   pub_semver: 1.3.2 # TRANSITIVE DEPENDENCY
   quiver: 0.27.0 # TRANSITIVE DEPENDENCY
@@ -61,8 +67,10 @@
   term_glyph: 1.0.0 # TRANSITIVE DEPENDENCY
   test: 0.12.26 # TRANSITIVE DEPENDENCY
   typed_data: 1.1.4 # TRANSITIVE DEPENDENCY
+  utf: 0.9.0+3 # TRANSITIVE DEPENDENCY
   vector_math: 2.0.5 # TRANSITIVE DEPENDENCY
   vm_service_client: 0.2.3 # TRANSITIVE DEPENDENCY
+  watcher: 0.9.7+6 # TRANSITIVE DEPENDENCY
   web_socket_channel: 1.0.6 # TRANSITIVE DEPENDENCY
   yaml: 2.1.13 # TRANSITIVE DEPENDENCY