Revert "refactor(testing): move common testing logic into test_injector"

This reverts commit b88a6d983f.

modules/angular2/test/web_workers/debug_tools/multi_client_server_message_bus.server.spec.dart

@@ -11,6 +11,7 @@ import "package:angular2/testing_internal.dart"
         iit,
         expect,
         beforeEach,
+        createTestInjector,
         beforeEachProviders,
         SpyObject,
         proxy;

modules/angular2/test/web_workers/debug_tools/single_client_server_message_bus.server.spec.dart

@@ -10,6 +10,7 @@ import "package:angular2/testing_internal.dart"
         it,
         expect,
         beforeEach,
+        createTestInjector,
         beforeEachProviders,
         SpyObject,
         proxy;

modules/angular2/test/web_workers/debug_tools/web_socket_message_bus_spec.dart

@@ -8,6 +8,7 @@ import "package:angular2/testing_internal.dart"
         it,
         expect,
         beforeEach,
+        createTestInjector,
         beforeEachProviders,
         SpyObject,
         proxy;