fix barback and polymer build warnings

pkg/pkg.status

Index: pkg/pkg.status
diff --git a/pkg/pkg.status b/pkg/pkg.status
index 529174485f6a7e957924af94561e2f7d9154293d..5848c9b35435dd8a34b1cdf9db33e49a510c9576 100644
--- a/pkg/pkg.status
+++ b/pkg/pkg.status
@@ -309,23 +309,6 @@ custom_element/test/analyzer_test: fail
 custom_element/test/analyzer_test: fail
 
 [ $compiler == dartanalyzer || $compiler == dart2analyzer ]
-barback/test/asset_id_test: StaticWarning
-barback/test/asset_set_test: StaticWarning
-barback/test/asset_test: StaticWarning
-barback/test/cancelable_future_test: StaticWarning
-barback/test/mutliset_test: StaticWarning
-barback/test/package_graph/add_remove_transform_test: StaticWarning
-barback/test/package_graph/errors_test: StaticWarning
-barback/test/package_graph/get_all_assets_test: StaticWarning
-barback/test/package_graph/group_test: StaticWarning
-barback/test/package_graph/many_parallel_transformers_test: StaticWarning
-barback/test/package_graph/repetition_test: StaticWarning
-barback/test/package_graph/source_test: StaticWarning
-barback/test/package_graph/transform_test: StaticWarning
-barback/test/stream_pool_test: StaticWarning
-barback/test/stream_replayer_test: StaticWarning
-barback/test/too_many_open_files_test: StaticWarning
-barback/test/transformer_test: StaticWarning
 csslib/test/big_1_test: StaticWarning
 csslib/test/compiler_test: StaticWarning
 csslib/test/declaration_test: StaticWarning
@@ -352,31 +335,6 @@ intl/test/date_time_format_file_odd_test: StaticWarning
 intl/test/date_time_format_http_request_test: StaticWarning
 intl/test/date_time_format_local_even_test: StaticWarning
 intl/test/date_time_format_local_odd_test: StaticWarning
-observe/test/transform_test: StaticWarning
-polymer/test/build/*: StaticWarning
-polymer/test/build/utils_test: Pass
-scheduled_test/test/descriptor/async_test: StaticWarning
-scheduled_test/test/descriptor/directory_test: StaticWarning
-scheduled_test/test/descriptor/file_test: StaticWarning
-scheduled_test/test/descriptor/nothing_test: StaticWarning
-scheduled_test/test/descriptor/pattern_test: StaticWarning
-scheduled_test/test/scheduled_future_matchers_test: StaticWarning
-scheduled_test/test/scheduled_process_test: StaticWarning
-scheduled_test/test/scheduled_test/abort_test: StaticWarning
-scheduled_test/test/scheduled_test/current_schedule_current_task_test: StaticWarning
-scheduled_test/test/scheduled_test/current_schedule_errors_test: StaticWarning
-scheduled_test/test/scheduled_test/current_schedule_state_test: StaticWarning
-scheduled_test/test/scheduled_test/nested_task_test: StaticWarning
-scheduled_test/test/scheduled_test/on_complete_test: StaticWarning
-scheduled_test/test/scheduled_test/on_exception_test: StaticWarning
-scheduled_test/test/scheduled_test/out_of_band_task_test: StaticWarning
-scheduled_test/test/scheduled_test/set_up_test: StaticWarning
-scheduled_test/test/scheduled_test/signal_error_test: StaticWarning
-scheduled_test/test/scheduled_test/simple_test: StaticWarning
-scheduled_test/test/scheduled_test/task_return_value_test: StaticWarning
-scheduled_test/test/scheduled_test/timeout_test: StaticWarning
-scheduled_test/test/scheduled_test/wrap_async_test: StaticWarning
-scheduled_test/test/scheduled_test/wrap_future_test: StaticWarning
 unittest/test/matchers_test: StaticWarning
 unittest/test/mock_test: StaticWarning
 watcher/test/directory_watcher_test: StaticWarning