build a precompiled SDK with canvas kit enabled (#17115)

web_sdk/BUILD.gn

@@ -28,6 +28,7 @@ web_engine_sources += [ "//flutter/lib/web_ui/lib/src/engine.dart" ]
 
 group("web_sdk") {
   deps = [
+    ":flutter_dartdevc_canvaskit_kernel_sdk",
     ":flutter_dartdevc_kernel_sdk",
     ":flutter_dartdevc_kernel_sdk_outline",
     ":web_engine_sources",
@@ -186,3 +187,57 @@ prebuilt_dart_action("flutter_dartdevc_kernel_sdk") {
     rebase_path("$root_out_dir/flutter_web_sdk/kernel/legacy/dart_sdk.js"),
   ]
 }
+
+# Compiles the DDC CanvasKit SDK's JS code.
+prebuilt_dart_action("flutter_dartdevc_canvaskit_kernel_sdk") {
+  deps = [
+    "//third_party/dart:create_sdk",
+    "//third_party/dart/pkg:pkg_files_stamp",
+    "//third_party/dart/utils/dartdevc:dartdevc_files_stamp",
+    "//third_party/dart/utils/dartdevc:dartdevc_sdk_patch_stamp",
+  ]
+
+  inputs = [ "sdk_rewriter.dart" ] + web_ui_sources + web_engine_sources
+
+  packages = "//third_party/dart/.packages"
+
+  script = "//third_party/dart/pkg/dev_compiler/bin/dartdevc.dart"
+
+  outputs = [
+    "$root_out_dir/flutter_web_sdk/kernel/amd-canvaskit/dart_sdk.js",
+    "$root_out_dir/flutter_web_sdk/kernel/amd-canvaskit/dart_sdk.js.map",
+  ]
+
+  args = [
+    "-k",
+    "--compile-sdk",
+    "dart:core",
+
+    # Additional Flutter web dart libraries
+    "dart:ui",
+    "dart:_engine",
+    "--no-summarize",
+    "--packages",
+    "file:///" + rebase_path("//third_party/dart/.packages"),
+    "--multi-root-scheme",
+    "org-dartlang-sdk",
+    "--multi-root",
+    "file:///" + rebase_path("$root_out_dir"),
+    "--multi-root-output-path",
+    rebase_path("$root_out_dir/"),
+    "--libraries-file",
+    "org-dartlang-sdk:///flutter_web_sdk/libraries.json",
+    "--inline-source-map",
+    "-DFLUTTER_WEB_USE_SKIA=true",
+    "--modules",
+    "amd",
+    "-o",
+    rebase_path(
+        "$root_out_dir/flutter_web_sdk/kernel/amd-canvaskit/dart_sdk.js"),
+    "--modules",
+    "legacy",
+    "-o",
+    rebase_path(
+        "$root_out_dir/flutter_web_sdk/kernel/legacy-canvaskit/dart_sdk.js"),
+  ]
+}