History init: add metrics and skip migration.

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 78a757d7251b25850c11d988425f1852ccb3ed1e..9bbad3299b87f97d5aa202a970650bb323a3eea5 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -23996,6 +23996,20 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="History.AttemptedToFixProfileError">
+  <owner>brettw@chromium.org</owner>
+  <summary>
+    Logged whenever history database initialization fails. The frequency of
+    logging will tell you the total failure rate. True indicate that we think
+    the database is non-recoverable and it will be deleted. It should be
+    re-created the next time Chrome is started. False indicates we think the
+    error is temporary (like out of disk space or file locked). Chrome will run
+    with no history database and nothing will be done to try to fix the error.
+    See History.InitializationFailureStep for which particular step of history
+    initialization failed.
+  </summary>
+</histogram>
+
 <histogram
     name="History.ClearBrowsingData.HistoryNoticeShownInFooterWhenUpdated"
     enum="BooleanShown">
@@ -24233,6 +24247,16 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="History.InitializationFailureStep" enum="HistoryInitStep">
+  <owner>brettw@chromium.org</owner>
+  <summary>
+    The phase of history initialization that failed. This histogram is only
+    logged on database initialization failure.
+    History.AttemptedToFixProfileError will tell how often initialization fails
+    overall.
+  </summary>
+</histogram>
+
 <histogram name="History.InMemoryDBItemCount">
   <owner>gab@chromium.org</owner>
   <summary>
@@ -24357,6 +24381,15 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="History.MigrateFailureFromVersion">
+  <owner>brettw@chromium.org</owner>
+  <summary>
+    History database version from which which history migration failed. If

[yzshen1, 2017/06/23 00:54:09]

nit: duplicate "which"

+    there are higher than normal migration failures, this histogram will
+    indicate which migration step failed.
+  </summary>
+</histogram>
+
 <histogram name="History.MonthlyHostCount">
   <owner>shess@chromium.org</owner>
   <summary>