Roll Dart VM. (#6472)

diff --git a/packages/flutter_tools/lib/src/devfs.dart b/packages/flutter_tools/lib/src/devfs.dart
index 0044c9d..23c9f5f 100644
--- a/packages/flutter_tools/lib/src/devfs.dart
+++ b/packages/flutter_tools/lib/src/devfs.dart
@@ -222,14 +222,19 @@
 
   Future<Null> _scheduleWrite(DevFSEntry entry,
                               DevFSProgressReporter progressReporter) async {
-    HttpClientRequest request = await _client.putUrl(httpAddress);
-    request.headers.removeAll(HttpHeaders.ACCEPT_ENCODING);
-    request.headers.add('dev_fs_name', fsName);
-    request.headers.add('dev_fs_path', entry.devicePath);
-    Stream<List<int>> contents = entry.contentsAsCompressedStream();
-    await request.addStream(contents);
-    HttpClientResponse response = await request.close();
-    await response.drain();
+    try {
+      HttpClientRequest request = await _client.putUrl(httpAddress);
+      request.headers.removeAll(HttpHeaders.ACCEPT_ENCODING);
+      request.headers.add('dev_fs_name', fsName);
+      request.headers.add('dev_fs_path_b64',
+                          BASE64.encode(UTF8.encode(entry.devicePath)));
+      Stream<List<int>> contents = entry.contentsAsCompressedStream();
+      await request.addStream(contents);
+      HttpClientResponse response = await request.close();
+      await response.drain();
+    } catch (e, stackTrace) {
+      printError('Error writing "${entry.devicePath}" to DevFS: $e\n$stackTrace');
+    }
     if (progressReporter != null) {
       _done++;
       progressReporter(_done, _max);