Remove '_ms' from measurement 'record_time_partial_invalidation_ms'

The '_ms' postfix was redundant with the 'ms' unit of the measurement,
and was inconsistent with other record_time measurements.

This is a safe rename because the measurement is neither used nor
monitored anywhere.

Change-Id: Ibe8d72c41b6116213e0cddbd61085bd9e438474b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2092672Reviewed-by: Caleb Rouleau <crouleau@chromium.org>
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#747978}

tools/perf/measurements/rasterize_and_record_micro.py

@@ -90,7 +90,7 @@ class RasterizeAndRecordMicro(legacy_page_test.LegacyPageTest):
                            record_time_caching_disabled)
     results.AddMeasurement('record_time_subsequence_caching_disabled', 'ms',
                            record_time_subsequence_caching_disabled)
-    results.AddMeasurement('record_time_partial_invalidation_ms', 'ms',
+    results.AddMeasurement('record_time_partial_invalidation', 'ms',
                            record_time_partial_invalidation)
 
     if self._report_detailed_results: