Drop diagnostics reference to out-dated database.

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 5fac893def29f6f59ebd0da562ae8eff089835e7..1bbcbb3c23f7c251cf412257b9ea9d791f094085 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -8567,6 +8567,16 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Diagnostics.Test.SQLiteIntegrityFavicons"
+    enum="DiagnosticsResult">
+  <owner>Please list the metric's owners. Add more owner tags as needed.</owner>

[Mark P, 2016/06/03 22:06:54]

Please fill in all these owner fields.

[Scott Hess - ex-Googler, 2016/06/03 22:51:35]

:-(.  I'll take on the SQLite ones (except for NSS, I think those are ChromeOS),
and the overall ran-the-tests ones.  I don't have enough understanding of what
this code is intended to do to confidently take overall ownership.

+  <summary>
+    Shows the success and failure rates of the SQLiteIntegrityFavicons test that
+    runs on recovery startups.  The test checks the integrity of the Favicons
+    database.
+  </summary>
+</histogram>
+
 <histogram name="Diagnostics.Test.SQLiteIntegrityHistory"
     enum="DiagnosticsResult">
   <owner>Please list the metric's owners. Add more owner tags as needed.</owner>
@@ -8597,13 +8607,13 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
-<histogram name="Diagnostics.Test.SQLiteIntegrityThumbnails"
+<histogram name="Diagnostics.Test.SQLiteIntegrityTopSites"
     enum="DiagnosticsResult">
   <owner>Please list the metric's owners. Add more owner tags as needed.</owner>
   <summary>
-    Shows the success and failure rates of the SQLiteIntegrityThumbnails test
-    that runs on recovery startups.  The test checks the integrity of the
-    Thumbnails database.
+    Shows the success and failure rates of the SQLiteIntegrityTopSites test that
+    runs on recovery startups.  The test checks the integrity of the TopSites
+    database.
   </summary>
 </histogram>
 
@@ -68289,8 +68299,9 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="16" label="SQLite Integrity History Test"/>
   <int value="17" label="SQLite Integrity Nss Cert Test"/>
   <int value="18" label="SQLite Integrity Nss Key Test"/>
-  <int value="19" label="SQLite Integrity Thumbnails Test"/>
+  <int value="19" label="SQLite Integrity Favicons Test"/>
   <int value="20" label="SQLite Integrity Web Data Test"/>
+  <int value="21" label="SQLite Integrity Top Sites Test"/>
 </enum>
 
 <enum name="DifferentPrimaryAccounts" type="int">