Flutter tools support for kernel transformer tracking Widget creation locations. (#13997)

diff --git a/packages/flutter_tools/lib/src/build_info.dart b/packages/flutter_tools/lib/src/build_info.dart
index 2598413..b552c8f 100644
--- a/packages/flutter_tools/lib/src/build_info.dart
+++ b/packages/flutter_tools/lib/src/build_info.dart
@@ -12,6 +12,7 @@
 class BuildInfo {
   const BuildInfo(this.mode, this.flavor,
       {this.previewDart2,
+      this.trackWidgetCreation,
       this.extraFrontEndOptions,
       this.extraGenSnapshotOptions,
       this.preferSharedLibrary,
@@ -29,6 +30,9 @@
   // Whether build should be done using Dart2 Frontend parser.
   final bool previewDart2;
 
+  /// Whether the build should track widget creation locations.
+  final bool trackWidgetCreation;
+
   /// Extra command-line options for front-end.
   final String extraFrontEndOptions;
 
@@ -68,6 +72,7 @@
   BuildInfo withTargetPlatform(TargetPlatform targetPlatform) =>
       new BuildInfo(mode, flavor,
           previewDart2: previewDart2,
+          trackWidgetCreation: trackWidgetCreation,
           extraFrontEndOptions: extraFrontEndOptions,
           extraGenSnapshotOptions: extraGenSnapshotOptions,
           preferSharedLibrary: preferSharedLibrary,