[Cleanup] Remove temporary Android histograms for # of minidumps at startup.

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index c2a2f5bfc680bbdc9249e41fd593e81938b36af9..b98a98cba4e86660b396975d4cf21b3bbc726675 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -70205,6 +70205,11 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 </histogram>
 
 <histogram name="Stability.Android.PendingMinidumpsOnStartup" units="minidumps">
+  <obsolete>
+    Deprecated in M60. Roughly 50% of Chrome startups that had *any* pending
+    minidumps had at least one pending minidump without any logcat output. About
+    5% had multiple minidumps without any logcat output.
+  </obsolete>
   <owner>isherman@chromium.org</owner>
   <summary>
     The number of un-uploaded minidumps present in the Android Crash Reports
@@ -70217,6 +70222,11 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 
 <histogram name="Stability.Android.PendingMinidumpsOnStartup.SansLogcat"
     units="minidumps">
+  <obsolete>
+    Deprecated in M60. Roughly 50% of Chrome startups that had *any* pending
+    minidumps had at least one pending minidump without any logcat output. About
+    5% had multiple minidumps without any logcat output.
+  </obsolete>
   <owner>isherman@chromium.org</owner>
   <summary>
     The number of un-uploaded minidumps present in the Android Crash Reports