diff --git a/bin/internal/engine.version b/bin/internal/engine.version
index a408a77..214d192 100644
--- a/bin/internal/engine.version
+++ b/bin/internal/engine.version
@@ -1 +1 @@
-d48085141c2f201b1c534e6926eb39bb52d9db3e
+b15a076b148a77ea875c3f42913b39ca1dc62c24
diff --git a/dev/bots/prepare_package.dart b/dev/bots/prepare_package.dart
index 6226ff4..627352f 100644
--- a/dev/bots/prepare_package.dart
+++ b/dev/bots/prepare_package.dart
@@ -370,6 +370,12 @@
     await _runGit(<String>['clean', '-f', '-X', '**/.packages']);
     /// Remove package_config files and any contents in .dart_tool
     await _runGit(<String>['clean', '-f', '-X', '**/.dart_tool']);
+    /// Remove git subfolder from .pub-cache, this contains the flutter goldens
+    /// and new flutter_gallery.
+    final Directory gitCache = Directory(path.join(flutterRoot.absolute.path, '.pub-cache', 'git'));
+    if (gitCache.existsSync()) {
+      gitCache.deleteSync(recursive: true);
+    }
   }
 
   /// Write the archive to the given output file.
diff --git a/packages/flutter/lib/src/foundation/_platform_web.dart b/packages/flutter/lib/src/foundation/_platform_web.dart
index 0bc21bb..5d28186 100644
--- a/packages/flutter/lib/src/foundation/_platform_web.dart
+++ b/packages/flutter/lib/src/foundation/_platform_web.dart
@@ -19,7 +19,7 @@
 }
 
 platform.TargetPlatform _browserPlatform() {
-  final String navigatorPlatform = html.window.navigator.platform.toLowerCase();
+  final String navigatorPlatform = html.window.navigator.platform?.toLowerCase() ?? '';
   if (navigatorPlatform.startsWith('mac')) {
     return platform.TargetPlatform.macOS;
   }