Tweaks to --hot mode

packages/flutter_tools/lib/src/devfs.dart

@@ -87,7 +87,7 @@ class ServiceProtocolDevFSOperations implements DevFSOperations {
                                                   'fileContents': fileContents
                                                });
     } catch (e) {
-      print('failed on ${entry.devicePath} $e');
+      printTrace('DevFS: Failed to write ${entry.devicePath}: $e');
     }
   }
 

packages/flutter_tools/lib/src/run.dart

@@ -345,9 +345,9 @@ class RunAndStayResident {
       });
     }
 
-    printStatus('DevFS: Updating files on device...');
+    Status devFSStatus = logger.startProgress('Updating files on device...');
     await _devFS.update();
-    printStatus('DevFS: Finished updating files on device...');
+    devFSStatus.stop(showElapsedTime: true);
     return true;
   }