Inline content_[tests/browser/android].gypi into GN build.

content/browser/notifications/notification_proto.gyp

Index: content/browser/notifications/notification_proto.gyp
diff --git a/content/browser/notifications/notification_proto.gyp b/content/browser/notifications/notification_proto.gyp
deleted file mode 100644
index effe03e10fb1a8b004b285f5e98ac1df4a5137d2..0000000000000000000000000000000000000000
--- a/content/browser/notifications/notification_proto.gyp
+++ /dev/null
@@ -1,17 +0,0 @@
-{
-  'targets': [
-    {
-      # GN version: //content/browser/notifications:notification_proto
-      'target_name': 'notification_proto',
-      'type': 'static_library',
-      'sources': [
-        'notification_database_data.proto',
-      ],
-      'variables': {
-        'proto_in_dir': '.',
-        'proto_out_dir': 'content/browser/notifications',
-      },
-      'includes': [ '../../../build/protoc.gypi' ]
-    },
-  ],
-}