do not strip symbols when building profile (#37210)

dev/devicelab/bin/tasks/module_test_ios.dart

@@ -59,6 +59,13 @@ Future<void> main() async {
         );
       }
 
+      if (await _hasDebugSymbols(ephemeralReleaseHostApp)) {
+        return TaskResult.failure(
+          "Ephemeral host app ${ephemeralReleaseHostApp.path}'s App.framework's "
+          "debug symbols weren't stripped in release mode"
+        );
+      }
+
       section('Clean build');
 
       await inDirectory(projectDir, () async {
@@ -92,6 +99,12 @@ Future<void> main() async {
         );
       }
 
+      if (!await _hasDebugSymbols(ephemeralProfileHostApp)) {
+        return TaskResult.failure(
+          "Ephemeral host app ${ephemeralProfileHostApp.path}'s App.framework does not contain debug symbols"
+        );
+      }
+
       section('Clean build');
 
       await inDirectory(projectDir, () async {
@@ -290,3 +303,26 @@ Future<bool> _isAppAotBuild(Directory app) async {
 
   return symbolTable.contains('kDartIsolateSnapshotInstructions');
 }
+
+Future<bool> _hasDebugSymbols(Directory app) async {
+  final String binary = path.join(
+    app.path,
+    'Frameworks',
+    'App.framework',
+    'App'
+  );
+
+  final String symbolTable = await eval(
+    'dsymutil',
+    <String> [
+      '--dump-debug-map',
+      binary,
+    ],
+    // The output is huge.
+    printStdout: false,
+  );
+
+  // Search for some random Flutter framework Dart function which should always
+  // be in App.framework.
+  return symbolTable.contains('BuildOwner_reassemble');
+}

packages/flutter_tools/bin/xcode_backend.sh

@@ -201,6 +201,7 @@ BuildApp() {
 
     RunCommand cp -r -- "${app_framework}" "${derived_dir}"
 
+    if [[ "${build_mode}" == "release" ]]; then
       StreamOutput " ├─Generating dSYM file..."
       # Xcode calls `symbols` during app store upload, which uses Spotlight to
       # find dSYM files for embedded frameworks. When it finds the dSYM file for
@@ -222,6 +223,7 @@ BuildApp() {
         exit -1
       fi
       StreamOutput "done"
+    fi
 
   else
     RunCommand mkdir -p -- "${derived_dir}/App.framework"