Omnibox.URLNavigationScheme - Exclude Paste-And-Go

*Not* renaming the histogram despite the change in semantics
because it looks like <0.5% of omnibox interactions are
paste-and-search or paste-and-go.  It's probably similar for this
metric: paste-and-go as a percent of all omnibox URL navigations.
This is small enough that I'm not concerned.  Noted the change
in semantics in the changelist description.

Tested using chrome://histograms

Bug: 1144343
Change-Id: I8e1bb4f37b339112174be3c2423fc47394a74661
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2536250Reviewed-by: Steven Bingler <bingler@chromium.org>
Reviewed-by: Jesse Doherty <jwd@chromium.org>
Commit-Queue: Mark Pearson <mpearson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#827320}

components/omnibox/browser/omnibox_edit_model.cc

@@ -895,9 +895,10 @@ void OmniboxEditModel::OpenMatch(AutocompleteMatch match,
     // For logging the below histogram, only record uses that depend on the
     // omnibox suggestion system, i.e., TYPED navigations.  That is, exclude
     // omnibox URL interactions that are treated as reloads or link-following
-    // (i.e., cut-and-paste of URLs).
+    // (i.e., cut-and-paste of URLs) or paste-and-go.
     if (ui::PageTransitionTypeIncludingQualifiersIs(
-            match.transition, ui::PAGE_TRANSITION_TYPED)) {
+            match.transition, ui::PAGE_TRANSITION_TYPED) &&
+        pasted_text.empty()) {
       navigation_metrics::RecordOmniboxURLNavigation(match.destination_url);
     }
 

tools/metrics/histograms/histograms_xml/omnibox/histograms.xml

@@ -956,6 +956,9 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
     not take into account any redirects that destination URL may do before
     finally serving a page. In other words, it's the scheme of the first request
     in a possible chain.
+
+    Due to a bug, recorded paste-and-go actions through M-88 (inclusive).
+    Excluded in M-89+.
   </summary>
 </histogram>