[e2e] Revert performance tracker utilities (flutter#2917)

(To be moved to flutter_test)

Author: CareF

packages/e2e/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.7.0
+
+* Move utilities for tracking frame performance in an e2e test to `flutter_test`.
+
 ## 0.6.3
 
 * Add customizable `flutter_driver` adaptor.

packages/e2e/lib/e2e_perf.dart

@@ -1,6 +1,6 @@
 name: e2e
 description: Runs tests that use the flutter_test API as integration tests.
-version: 0.6.3
+version: 0.7.0
 homepage: https://github.com/flutter/plugins/tree/master/packages/e2e
 
 environment: