Revert "Switch on building devtools from source when building the Dart SDK"

This reverts commit d0d8184d1a.

Reason for revert: Doesn't build in Flutter
https://logs.chromium.org/logs/flutter/buildbucket/cr-buildbucket/8683246937886984145/+/u/gn_--target-dir_ci_host_debug_--runtime-mode_debug_--no-prebuilt-dart-sdk_--build-embedder-examples_--no-lto_--rbe_--no-goma_--rbe-server-address_unix:___b_s_w_ir_x_w_rc_rbebn74b14k_reproxy.sock/stdout

Original change's description:
> Switch on building devtools from source when building the Dart SDK
>
> Fixes https://github.com/flutter/devtools/issues/9786
>
> See go/moving-devtools-to-dart-sdk-2025.
>
> In this change, we make the source of devtools be configurable, in
> actions like build_sdk.
>
> If `build_devtools_from_sources` is true, we build local devtools,
> and if false, we continue to use the prebuilt sources.
>
> This may be an intermediate step, while we test out building devtools
> from source. Or it may be permanently be a choice, if we keep building
> with CIPD.
>
> Change-Id: I7b46d6359c69b34f316e59dccc475e211a18f965
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/498640
> Reviewed-by: Alexander Aprelev <aam@google.com>
> Commit-Queue: Samuel Rawlins <srawlins@google.com>

Change-Id: I20381d6bf1d9cba192c46efde99cb57dc75e7cae
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/499160
Reviewed-by: Samuel Rawlins <srawlins@google.com>
Commit-Queue: Liam Appelbe <liama@google.com>
Bot-Commit: rubber-stamper@appspot.gserviceaccount.com <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Nate Biggs <natebiggs@google.com>

sdk/BUILD.gn

@@ -13,7 +13,6 @@
 # or ":copy_libraries" may delete/overwrite your addition, and the build will
 # fail.
 
-import("../build/config/gclient_args.gni")
 import("../build/dart/copy_tree.gni")
 import("../build/executable_suffix.gni")
 import("../sdk_args.gni")
@@ -311,8 +310,7 @@ copy_tree("copy_prebuilt_devtools") {
 
 # This action compiles the devtools app from sources.
 action("build_devtools") {
-  visibility = [ ":create_common_sdk" ]
-  output = "$root_out_dir/$dart_sdk_output/bin/resources/devtools"
+  output = "$root_out_dir/$dart_sdk_output/web/devtools_app"
   outputs = [ output ]
   script = "../tools/build_devtools.py"
   args = [
@@ -883,6 +881,7 @@ group("create_common_sdk") {
     ":copy_headers",
     ":copy_libraries_specification",
     ":copy_license",
+    ":copy_prebuilt_devtools",
     ":copy_readme",
     ":copy_sdk_packages_yaml",
     ":copy_vm_dill_files",
@@ -892,12 +891,6 @@ group("create_common_sdk") {
     ":write_version_file",
   ]
 
-  if (build_devtools_from_sources) {
-    public_deps += [ ":build_devtools" ]
-  } else {
-    public_deps += [ ":copy_prebuilt_devtools" ]
-  }
-
   # We do not support AOT on ia32 and should therefore not add the
   # dart native compilation files since there is no AOT compiler/runtime
   # available.

tools/build_devtools.py

@@ -93,7 +93,6 @@ def main():
             elif os.path.exists(args.output):
                 os.remove(args.output)
             shutil.copytree(build_dir, args.output)
-            shutil.rmtree(build_dir)
 
         print('DevTools build successful.')
         return 0