Mark SafeBrowsing.ModuleBaseRelocation as obsolete

This histogram is deprecated and no longer need to be recorded.

Bug: 1089422
Change-Id: I9c29449b3080535e1451163f1b76c65139df792d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2225536Reviewed-by: proberge <proberge@chromium.org>
Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Commit-Queue: Chris Sharp <csharp@chromium.org>
Cr-Commit-Position: refs/heads/master@{#773851}

chrome/browser/safe_browsing/incident_reporting/module_integrity_verifier_win.cc

@@ -251,7 +251,6 @@ bool EnumRelocsCallback(const base::win::PEImage& mem_peimage,
     default:
       // TODO(robertshield): Find a reliable description of the behaviour of the
       // remaining types of relocation and handle them.
-      base::UmaHistogramSparse("SafeBrowsing.ModuleBaseRelocation", type);
       state->unknown_reloc_type = true;
       break;
   }

tools/metrics/histograms/histograms.xml

@@ -141401,6 +141401,9 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 
 <histogram name="SafeBrowsing.ModuleBaseRelocation" units="BaseRelocationType"
     expires_after="M85">
+  <obsolete>
+    No longer used. Removed 2020-06.
+  </obsolete>
   <owner>csharp@chromium.org</owner>
   <owner>proberge@google.com</owner>
   <summary>