Add owners for new omnibox metrics.

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 86275e44d40e63364085c18179a18ec78aa33ecd..b067f5f4645366ac20ee1ae243eb7944f7af1001 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -44883,6 +44883,8 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 <histogram
     name="Omnibox.SuggestionUsed.Search.Experimental.ForegroundToFirstMeaningfulPaint.Prerender"
     units="ms">
+  <owner>lpy@chromium.org</owner>
+  <owner>mpearson@chromium.org</owner>
   <summary>
     Measures the time from the page first appearing in the foreground to its
     first meaningful paint. Only recorded on navigations that use a prerender
@@ -44893,6 +44895,8 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 <histogram
     name="Omnibox.SuggestionUsed.Search.Experimental.NavigationToFirstMeaningfulPaint"
     units="ms">
+  <owner>lpy@chromium.org</owner>
+  <owner>mpearson@chromium.org</owner>
   <summary>
     Measures the time from navigation start to first meaningful paint. Only
     recorded for a search query suggestion selected from the omnibox.
@@ -44902,6 +44906,8 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 <histogram
     name="Omnibox.SuggestionUsed.Search.ForegroundToFirstContentfulPaint.Prerender"
     units="ms">
+  <owner>lpy@chromium.org</owner>
+  <owner>mpearson@chromium.org</owner>
   <summary>
     Measures the time from the page first appearing in the foreground to its
     first contentful paint. Only recorded on navigations that use a prerender
@@ -44912,6 +44918,8 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 <histogram
     name="Omnibox.SuggestionUsed.Search.NavigationToFirstContentfulPaint"
     units="ms">
+  <owner>lpy@chromium.org</owner>
+  <owner>mpearson@chromium.org</owner>
   <summary>
     Measures the time from navigation start to first contentful paint. Only
     recorded for a search query suggestion selected from the omnibox.
@@ -44921,6 +44929,8 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 <histogram
     name="Omnibox.SuggestionUsed.Search.NavigationToFirstForeground.Prerender"
     units="ms">
+  <owner>lpy@chromium.org</owner>
+  <owner>mpearson@chromium.org</owner>
   <summary>
     Measures the time from a page being navigated to in prerender to it first
     showing up in foreground. Only recorded on navigations that used a prerender
@@ -44941,6 +44951,8 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 <histogram
     name="Omnibox.SuggestionUsed.URL.Experimental.ForegroundToFirstMeaningfulPaint.Prerender"
     units="ms">
+  <owner>lpy@chromium.org</owner>
+  <owner>mpearson@chromium.org</owner>
   <summary>
     Measures the time from the page first appearing in the foreground to its
     first meaningful paint. Only recorded on navigations that use a prerender
@@ -44951,6 +44963,8 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 <histogram
     name="Omnibox.SuggestionUsed.URL.Experimental.NavigationToFirstMeaningfulPaint"
     units="ms">
+  <owner>lpy@chromium.org</owner>
+  <owner>mpearson@chromium.org</owner>
   <summary>
     Measures the time from navigation start to first meaningful paint. Only
     recorded for a URL suggestion selected from the omnibox.
@@ -44960,6 +44974,8 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 <histogram
     name="Omnibox.SuggestionUsed.URL.ForegroundToFirstContentfulPaint.Prerender"
     units="ms">
+  <owner>lpy@chromium.org</owner>
+  <owner>mpearson@chromium.org</owner>
   <summary>
     Measures the time from the page first appearing in the foreground to its
     first contentful paint. Only recorded on navigations that use a prerender
@@ -44969,6 +44985,8 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 
 <histogram name="Omnibox.SuggestionUsed.URL.NavigationToFirstContentfulPaint"
     units="ms">
+  <owner>lpy@chromium.org</owner>
+  <owner>mpearson@chromium.org</owner>
   <summary>
     Measures the time from navigation start to first contentful paint. Only
     recorded for a URL suggestion selected from the omnibox.
@@ -44978,6 +44996,8 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 <histogram
     name="Omnibox.SuggestionUsed.URL.NavigationToFirstForeground.Prerender"
     units="ms">
+  <owner>lpy@chromium.org</owner>
+  <owner>mpearson@chromium.org</owner>
   <summary>
     Measures the time from a page being navigated to in prerender to it first
     showing up in foreground. Only recorded on navigations that used a prerender