Focus on the default browser option when opening the Win10 settings page.

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 23b9020f207406be4fc41779d9ab357f4ff73a61..56a91b14c12d76278d796e8ffb66560524b3463b 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -250,6 +250,15 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="ActivateSettings.ErrorHresult" enum="Hresult">

[Alexei Svitkine (slow), 2016/02/16 19:09:40]

Can this histogram be nested under an existing prefix? e.g. under Installer.*

[grt (UTC plus 2), 2016/02/16 21:08:45]

I could see putting it in "Platform.*" since it's a
Cr-Internals-PlatformIntegration sort of thing. That prefix seems to be
primarily (exclusively?) used by CrOS metrics at the moment, though. Is it okay
to jump into someone else's prefix like that?

[Alexei Svitkine (slow), 2016/02/16 21:25:54]

Yeah Platform has been used for CrOS so I think it would be confusing to put
other stuff there. Maybe just put it under Windows.*?

[grt (UTC plus 2), 2016/02/16 21:25:59]

I've moved it under "DefaultBrowser." after pmonette's excellent suggestion.

+  <owner>pmonette@chromium.org</owner>
+  <owner>grt@chromium.org</owner>
+  <summary>
+    The HRESULT from ActivateApplication when opening the Win10+ settings page
+    fails.
+  </summary>
+</histogram>
+
 <histogram name="Android.ArmFpu" enum="AndroidArmFpu">
   <owner>fdegans@chromium.org</owner>
   <summary>
@@ -68484,6 +68493,7 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="-2147023436" label="ERROR_TIMEOUT"/>
   <int value="-2147023179" label="RPC_S_UNKNOWN_IF"/>
   <int value="-2147023174" label="RPC_S_SERVER_UNAVAILABLE"/>
+  <int value="-2147009295" label="ERROR_INSTALL_PACKAGE_NOT_FOUND"/>
   <int value="-2146959355" label="CO_E_SERVER_EXEC_FAILURE"/>
 </enum>