Revert "Sync packages from shelf mono repo"

This reverts commit 243ac04.

Reason for revert: Breaks roll to flutter engine still.

Original change's description:
> Sync packages from shelf mono repo
>
> Keep the DEPS entries and directories for the old locations for these
> packages, but ignore them in `generate_package_config`. Removing the
> hashes and directories would invalidate the DEPS file in the flutter
> engine repository.
>
> Add the `shelf` repository to the specially handled directories with
> nested packages in `generate_package_config`.
>
> Update path dependencies in pubspecs to the new location.
>
> Reland of https://dart-review.googlesource.com/c/sdk/+/243929
> without the removal of the old directory locations.
>
> R=​devoncarew@google.com
>
> Change-Id: I3d3b3eb0722f3eba518a6a1034ed9c24f83c70f0
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/244300
> Reviewed-by: Devon Carew <devoncarew@google.com>
> Commit-Queue: Nate Bosch <nbosch@google.com>

TBR=devoncarew@google.com,nbosch@google.com

Change-Id: Ied6d9aa685208eddea6d82d04ca8876937651051
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/244302
Reviewed-by: Nate Bosch <nbosch@google.com>
Commit-Queue: Devon Carew <devoncarew@google.com>
Reviewed-by: Devon Carew <devoncarew@google.com>

DEPS

@@ -144,7 +144,7 @@ vars = {
   "rust_revision": "b7856f695d65a8ebc846754f97d15814bcb1c244",
   "shelf_packages_handler_rev": "78302e67c035047e6348e692b0c1182131f0fe35",
   "shelf_proxy_rev": "124615d0614b38814970aa9638725d9d6b435268",
-  "shelf_rev": "6d1f24da2f85ba221dda3cfaadb4d3fc043e8eec",
+  "shelf_rev": "78ac724a7944700340a3cef28c84bccbe62e9367",
   "shelf_static_rev": "202ec1a53c9a830c17cf3b718d089cf7eba568ad",
   "shelf_web_socket_rev": "24fb8a04befa75a94ac63a27047b231d1a22aab4",
   "source_map_stack_trace_rev": "8eabd96b1811e30a11d3c54c9b4afae4fb72e98f",

pkg/compiler/pubspec.yaml

@@ -98,9 +98,9 @@ dependency_overrides:
   protobuf:
     path: ../../third_party/pkg/protobuf/protobuf
   shelf:
-    path: ../../third_party/pkg/shelf/pkgs/shelf
+    path: ../../third_party/pkg/shelf
   shelf_static:
-    path: ../../third_party/pkg/shelf/pkgs/shelf_static
+    path: ../../third_party/pkg/shelf_static
   source_span:
     path: ../../third_party/pkg/source_span
   stack_trace:

pkg/dev_compiler/pubspec.yaml

@@ -52,6 +52,6 @@ dependency_overrides:
   meta:
     path: ../meta
   shelf:
-    path: ../../third_party/pkg/shelf/pkgs/shelf
+    path: ../../third_party/pkg/shelf
   http_multi_server:
     path: ../../third_party/pkg/http_multi_server

tools/generate_package_config.dart

@@ -20,7 +20,6 @@ void main(List<String> args) {
     ...listSubdirectories(platform('third_party/pkg')),
     ...listSubdirectories(platform('third_party/pkg/file/packages')),
     ...listSubdirectories(platform('third_party/pkg/test/pkgs')),
-    ...listSubdirectories(platform('third_party/pkg/shelf/pkgs')),
     platform('pkg/vm_service/test/test_package'),
     platform('runtime/observatory_2'),
     platform(
@@ -37,12 +36,6 @@ void main(List<String> args) {
   // Remove the package at the top-level of the package:file monorepo.
   packageDirs.remove(platform('third_party/pkg/file'));
 
-  // Temporarily ignored copies of shelf mono repo package
-  packageDirs.remove(platform('third_party/pkg/shelf_packages_handler'));
-  packageDirs.remove(platform('third_party/pkg/shelf_proxy'));
-  packageDirs.remove(platform('third_party/pkg/shelf_static'));
-  packageDirs.remove(platform('third_party/pkg/shelf_web_socket'));
-
   var cfePackageDirs = [
     platform('pkg/front_end/testcases'),
   ];