Add histograms for session startup enum and number of URLs to open.

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 7b4d26dddfcbc1d89717a0e0a2d05291d52a6f73..2cb02f7ffe699891ac6655ceccde9d4f16878dee 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -12828,6 +12828,17 @@ other types of suffix sets.
   </summary>
 </histogram>
 
+<histogram name="Settings.StartupPageLoadSettings" enum="SessionStartupPref">
+  <summary>The startup page settings when a profile is loaded.</summary>
+</histogram>
+
+<histogram name="Settings.StartupPageLoadURLs">
+  <summary>
+    The number of URLs to be loaded on startup when a profile is loaded, if the
+    startup page setting is set to load URLs.
+  </summary>
+</histogram>
+
 <histogram name="SimpleCache.CheckCRCResult" enum="CheckCRCResult">
   <summary>
     Whether or not the CRC was checked at the moment when the last reference to
@@ -20507,6 +20518,13 @@ other types of suffix sets.
   <int value="1" label="Scroll on main-thread"/>
 </enum>
 
+<enum name="SessionStartupPref" type="int">
+  <int value="0" label="Open home page (unused)"/>
+  <int value="1" label="Continue from last opened pages"/>
+  <int value="4" label="Open URLs"/>
+  <int value="5" label="Open new tab page"/>
+</enum>
+
 <enum name="ShillTerminationActionResult" type="int">
   <summary>
     The termination action result types come from TerminationActionResult in