[sync] Remove Sync.ModelTypeRedundantPut

The histogram has collected sufficient data already.

Change-Id: I5aeec8038cb25b301d4cee7b86143a2b84dede6a
Bug: 1130649
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2435112Reviewed-by: Brian White <bcwhite@chromium.org>
Commit-Queue: Mikel Astiz <mastiz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#812007}

components/sync/model_impl/client_tag_based_model_type_processor.cc

@@ -390,8 +390,6 @@ void ClientTagBasedModelTypeProcessor::Put(
     }
   } else if (entity->MatchesData(*data)) {
     // Ignore changes that don't actually change anything.
-    UMA_HISTOGRAM_ENUMERATION("Sync.ModelTypeRedundantPut",
-                              ModelTypeHistogramValue(type_));
     return;
   }
 

tools/metrics/histograms/histograms_xml/obsolete_histograms.xml

@@ -81412,6 +81412,19 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
   </summary>
 </histogram>
 
+<histogram name="Sync.ModelTypeRedundantPut" enum="SyncModelTypes"
+    expires_after="2020-11-01">
+  <obsolete>
+    Removed as of 10/2020.
+  </obsolete>
+  <owner>mastiz@chromium.org</owner>
+  <owner>jkrcal@chromium.org</owner>
+  <summary>
+    Records the model type when a local change is made and sync optimized it
+    away because nothing actually changed.
+  </summary>
+</histogram>
+
 <histogram name="Sync.ModelTypeStoreCommitCount" enum="SyncModelTypes"
     expires_after="2019-07-19">
   <obsolete>

tools/metrics/histograms/histograms_xml/sync/histograms.xml

@@ -564,16 +564,6 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
   </summary>
 </histogram>
 
-<histogram name="Sync.ModelTypeRedundantPut" enum="SyncModelTypes"
-    expires_after="2020-11-01">
-  <owner>mastiz@chromium.org</owner>
-  <owner>jkrcal@chromium.org</owner>
-  <summary>
-    Records the model type when a local change is made and sync optimized it
-    away because nothing actually changed.
-  </summary>
-</histogram>
-
 <histogram base="true" name="Sync.ModelTypeStoreCommitWriteBatchOutcome"
     enum="LevelDBStatus" expires_after="2021-01-31">
 <!-- Name completed by histogram_suffixes name="SyncModelType" -->