Support relative paths in path dependencies.

utils/pub/lock_file.dart

Index: utils/pub/lock_file.dart
diff --git a/utils/pub/lock_file.dart b/utils/pub/lock_file.dart
index 23e709993e18d1bb8499f3ba5844b6364f9e214e..e9c12e089245577af8505cbc67df96dc10cc3a22 100644
--- a/utils/pub/lock_file.dart
+++ b/utils/pub/lock_file.dart
@@ -22,7 +22,8 @@ class LockFile {
     : packages = <String, PackageId>{};
 
   /// Parses the lockfile whose text is [contents].
-  factory LockFile.parse(String contents, SourceRegistry sources) {
+  factory LockFile.parse(String filePath, String contents,
+      SourceRegistry sources) {
     var packages = <String, PackageId>{};
 
     if (contents.trim() == '') return new LockFile.empty();
@@ -54,7 +55,8 @@ class LockFile {
           throw new FormatException('Package $name is missing a description.');
         }
         var description = spec['description'];
-        source.validateDescription(description, fromLockFile: true);
+        description = source.parseDescription(filePath, description,
+            fromLockFile: true);
 
         var id = new PackageId(name, source, version, description);