Histogram versions and extended error codes for SQLite databases.

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 535d3bcc75c299c05a279f2200f158f49038f860..5e79d3b5faa3aecb43fbbf2a8c85605aa30c63b2 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -6763,12 +6763,24 @@ other types of suffix sets.
   <summary>Error codes returned by sqlite for the appcache db.</summary>
 </histogram>
 
+<histogram name="Sqlite.AppCache.Version">
+  <summary>Appcache db version at startup.</summary>

[jar (doing other things), 2013/05/07 23:46:41]

For each of these histograms.... can you give me a sense of how many distinct
buckets we'd expect to see across our fleet of Chrome users?  Are these things
like "about 3-5 versions a year" or "each day a new version is invented??"

+</histogram>
+
 <histogram name="Sqlite.Cookie.Error" enum="SqliteErrorCode">
-  <summary>Error codes returned by sqlite the cookie db.</summary>
+  <summary>Error codes returned by sqlite for the cookie db.</summary>
+</histogram>
+
+<histogram name="Sqlite.Cookie.Version">
+  <summary>Cookie db version at startup.</summary>
 </histogram>
 
 <histogram name="Sqlite.DatabaseTracker.Error" enum="SqliteErrorCode">
-  <summary>Error codes returned by sqlite the websqldb tracker db.</summary>
+  <summary>Error codes returned by sqlite for the websqldb tracker db.</summary>
+</histogram>
+
+<histogram name="Sqlite.DatabaseTracker.Version">
+  <summary>Websqldb tracker db version at startup.</summary>
 </histogram>
 
 <histogram name="Sqlite.DomainBoundCerts.Error" enum="SqliteErrorCode">
@@ -6777,36 +6789,74 @@ other types of suffix sets.
   </summary>
 </histogram>
 
+<histogram name="Sqlite.DomainBoundCerts.Version">
+  <summary>Domain-bound certs db version at startup.</summary>
+</histogram>
+
 <histogram name="Sqlite.DomStorageDatabase.Error" enum="SqliteErrorCode">
   <summary>Error codes returned by sqlite for the domstorage db.</summary>
 </histogram>
 
+<histogram name="Sqlite.DomStorageDatabase.Version">
+  <summary>Domstorage db version at startup.</summary>
+</histogram>
+
 <histogram name="Sqlite.Error" enum="SqliteErrorCode">
   <summary>Error codes returned by sqlite for all databases.</summary>
 </histogram>
 
 <histogram name="Sqlite.Error.IOERR" enum="SqliteIOERRCode">
-  <summary>Error codes returned by sqlite for all databases.</summary>
+  <summary>
+    Extended SQLITE_IOERR codes returned by sqlite for all databases.
+  </summary>
 </histogram>
 
 <histogram name="Sqlite.History.Error" enum="SqliteErrorCode">
   <summary>Error codes returned by sqlite for the history db.</summary>
 </histogram>
 
+<histogram name="Sqlite.History.Version">
+  <summary>History db version at startup.</summary>
+</histogram>
+
 <histogram name="Sqlite.Quota.Error" enum="SqliteErrorCode">
   <summary>Error codes returned by sqlite for the quota db.</summary>
 </histogram>
 
+<histogram name="Sqlite.Quota.Version">
+  <summary>Quota db version at startup.</summary>
+</histogram>
+
 <histogram name="Sqlite.Text.Error" enum="SqliteErrorCode">
-  <summary>Error codes returned by sqlite the full text db.</summary>
+  <summary>Error codes returned by sqlite for the full text db.</summary>
+</histogram>
+
+<histogram name="Sqlite.Text.Version">
+  <summary>Full-text db version at startup.</summary>
 </histogram>
 
 <histogram name="Sqlite.Thumbnail.Error" enum="SqliteErrorCode">
   <summary>Error codes returned by sqlite for the thumbnail db.</summary>
 </histogram>
 
+<histogram name="Sqlite.Thumbnail.Version">
+  <summary>Thumbnail db version at startup.</summary>
+</histogram>
+
+<histogram name="Sqlite.TopSites.Error" enum="SqliteErrorCode">
+  <summary>Error codes returned by sqlite for the top sites db.</summary>
+</histogram>
+
+<histogram name="Sqlite.TopSites.Version">
+  <summary>Top sites db version at startup.</summary>
+</histogram>
+
 <histogram name="Sqlite.Web.Error" enum="SqliteErrorCode">
-  <summary>Error codes returned by sqlite the web db.</summary>
+  <summary>Error codes returned by sqlite for the web db.</summary>
+</histogram>
+
+<histogram name="Sqlite.Web.Version">
+  <summary>Web db version at startup.</summary>
 </histogram>
 
 <histogram name="Tab.SwitchedToForegroundAge" units="ms">