Add resetIds (#56)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 07f3f77..7a198db 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.5.15
+
+* Add `BasicInfo.resetIds` to free internal cache used for id uniqueness.
+
 ## 0.5.14
 * Updates `coverage_log_server.dart` and `live_code_size_analysis.dart` to make
   them strong clean and match the latest changes in dart2js.
diff --git a/lib/info.dart b/lib/info.dart
index 05ba195..8bc7e4c 100644
--- a/lib/info.dart
+++ b/lib/info.dart
@@ -54,6 +54,10 @@
 //  - inputSize: bytes used in the Dart source program
 abstract class BasicInfo implements Info {
   static final Set<int> _ids = new Set<int>();
+
+  /// Frees internal cache used for id uniqueness.
+  static void resetIds() => BasicInfo._ids.clear();
+
   final InfoKind kind;
 
   int _id;
diff --git a/pubspec.yaml b/pubspec.yaml
index 645ea39..1677ba8 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: dart2js_info
-version: 0.5.14
+version: 0.5.15
 
 description: >
   Libraries and tools to process data produced when running dart2js with