update dependencies to use url style paths

pkg/dev_compiler/lib/src/compiler/command.dart

Index: pkg/dev_compiler/lib/src/compiler/command.dart
diff --git a/pkg/dev_compiler/lib/src/compiler/command.dart b/pkg/dev_compiler/lib/src/compiler/command.dart
index 6170f6d85f7631e774f687cf7086b235ba7bd109..cd340db8154888a41ab01eb7940eb3a228509f73 100644
--- a/pkg/dev_compiler/lib/src/compiler/command.dart
+++ b/pkg/dev_compiler/lib/src/compiler/command.dart
@@ -221,7 +221,8 @@ String _moduleForLibrary(
     if (path.isWithin(moduleRoot, summaryPath) && summaryPath.endsWith(ext)) {
       var buildUnitPath =
           summaryPath.substring(0, summaryPath.length - ext.length);
-      return path.relative(buildUnitPath, from: moduleRoot);
+      return path.url
+          .joinAll(path.split(path.relative(buildUnitPath, from: moduleRoot)));
     }
 
     _usageException('Imported file ${source.uri} is not within the module root '