Enable ash shell and unit tests in GN build.

ui/views_content_client/views_content_client.gyp

Index: ui/views_content_client/views_content_client.gyp
diff --git a/ui/views_content_client/views_content_client.gyp b/ui/views_content_client/views_content_client.gyp
index 1773c2af63dfeddfd35ae62637036807e795960b..cd53207ea06504a88589541f8d2e128c60de3382 100644
--- a/ui/views_content_client/views_content_client.gyp
+++ b/ui/views_content_client/views_content_client.gyp
@@ -7,6 +7,7 @@
   },
   'targets': [
     {
+      # GN version: //ui/views_content_client
       'target_name': 'views_content_client',
       'type': '<(component)',
       'dependencies': [
@@ -29,6 +30,7 @@
         'VIEWS_CONTENT_CLIENT_IMPLEMENTATION',
       ],
       'sources': [
+        # Note: sources list duplicated in GN build.
         'views_content_browser_client.cc',
         'views_content_browser_client.h',
         'views_content_client.cc',