Add remaining LE credential histograms

Add the histogram entries for remaining LE Credential operations (Check,
Remove, Reset, ResetTree, Sync, SyncOutcome) and their actions (if
applicable).

The CL that introduced the code that generates this data
is http://crrev.com/c/1093957

Bug: chromium:809749
Test: None
Change-Id: I3959e1696fa3df963f16d834c5d2fdbe8966633f
Reviewed-on: https://chromium-review.googlesource.com/1178473
Commit-Queue: Prashant Malani <pmalani@chromium.org>
Reviewed-by: Brian White <bcwhite@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584201}

tools/metrics/histograms/histograms.xml

@@ -121384,6 +121384,7 @@ uploading your change for review.
   <suffix name="Reset"/>
   <suffix name="ResetTree"/>
   <suffix name="Sync"/>
+  <suffix name="SyncOutcome"/>
   <affected-histogram name="Cryptohome.LECredential"/>
 </histogram_suffixes>
 
@@ -121393,7 +121394,12 @@ uploading your change for review.
   <suffix name="BackendReplayLog"/>
   <suffix name="LoadFromDisk"/>
   <suffix name="SaveToDisk"/>
+  <affected-histogram name="Cryptohome.LECredential.Check"/>
   <affected-histogram name="Cryptohome.LECredential.Insert"/>
+  <affected-histogram name="Cryptohome.LECredential.Remove"/>
+  <affected-histogram name="Cryptohome.LECredential.Reset"/>
+  <affected-histogram name="Cryptohome.LECredential.ResetTree"/>
+  <affected-histogram name="Cryptohome.LECredential.Sync"/>
 </histogram_suffixes>
 
 <histogram_suffixes name="LevelDBBFEMethods" separator=".">