Add 'flutter_release' patch_sdk mode to patch_sdk

tools/patch_sdk.dart

Index: tools/patch_sdk.dart
diff --git a/tools/patch_sdk.dart b/tools/patch_sdk.dart
index 3ff5d4828b2bca8ce046143d8cba024b086a60f6..03a4ffd10a9ecad3a88bb8182f24fdae042614d6 100644
--- a/tools/patch_sdk.dart
+++ b/tools/patch_sdk.dart
@@ -74,10 +74,11 @@ void usage(String mode) {
   exit(1);
 }
 
-const validModes = const ['vm', 'dart2js', 'flutter'];
+const validModes = const ['vm', 'dart2js', 'flutter', 'flutter_release'];
 String mode;
 bool get forVm => mode == 'vm';
-bool get forFlutter => mode == 'flutter';
+bool get forFlutter => mode == 'flutter' || mode == 'flutter_release';
+bool get forFlutterRelease => mode == 'flutter_release';
 bool get forDart2js => mode == 'dart2js';
 
 Future _main(List<String> argv) async {
@@ -123,7 +124,9 @@ Future _main(List<String> argv) async {
     await fasta.compilePlatform(outDirUri, platform,
         packages: packages,
         outlineOutput: outline,
-        backendTarget: forVm ? 'vm_fasta' : 'flutter_fasta');
+        backendTarget: forVm
+            ? 'vm_fasta'
+            : forFlutterRelease ? 'flutter_fasta_release' : 'flutter_fasta');
   } else {
     await dart2js.compilePlatform(outDirUri, platform,
         packages: packages, outlineOutput: outline);
@@ -226,7 +229,28 @@ String _updateLibraryMetadata(String sdkOut, String libContents) {
           implementation: true,
           documented: false,
           platforms: VM_PLATFORM),
+
     ''');
+
+    if (!forFlutterRelease) {
+      // vmservice should be present unless we build release flavor of Flutter.
+      extraLibraries.write('''
+       "_vmservice": const LibraryInfo(
+           "vmservice/vmservice.dart",
+           categories: "Client,Server",
+           implementation: true,
+           documented: false,
+           platforms: VM_PLATFORM),
+
+        "vmservice_sky": const LibraryInfo(
+            "vmservice_sky/vmservice_io.dart",
+            categories: "Client,Server",
+            implementation: true,
+            documented: false,
+            platforms: VM_PLATFORM),
+
+      ''');
+    }
   }
 
   libContents = libContents.replaceAll(
@@ -265,6 +289,19 @@ _copyExtraLibraries(String sdkOut, Map<String, String> locations) {
       _writeSync(uiLibraryOut, readInputFile(file.path));
     }
     locations['ui'] = 'ui/ui.dart';
+
+    if (!forFlutterRelease) {
+      // vmservice should be present unless we build release flavor of Flutter.
+      for (var file in ['loader.dart', 'server.dart', 'vmservice_io.dart']) {
+        var libraryIn = path.join(dartDir, 'runtime', 'bin', 'vmservice', file);
+        var libraryOut = path.join(sdkOut, 'vmservice_io', file);
+        _writeSync(libraryOut, readInputFile(libraryIn));
+      }
+
+      locations['vmservice_sky'] =
+          path.join('vmservice_io', 'vmservice_io.dart');
+      locations['_vmservice'] = path.join('vmservice', 'vmservice.dart');
+    }
   }
 }