Ensure nearby URL count metric is properly initialized

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 10a462fc7dd2b11959222cb84f0f8cbc6ac321e1..3daca0a03d60520b188f97acf7d3eae658658d81 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -42940,6 +42940,20 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Omnibox.PhysicalWebProvider.SuggestionUsedWithoutOmniboxFocus"
+    enum="Boolean">
+  <owner>cco3@chromium.org</owner>
+  <owner>mattreynolds@chromium.org</owner>
+  <owner>mmocny@chromium.org</owner>
+  <summary>
+    Records a boolean value indicating whether the Physical Web provider was
+    invoked by focusing the omnibox during the current omnibox session. This is
+    unexpected; it's probably a bug somwhere. Recorded when the user selects an
+    omnibox suggestion. Does not record when the Physical Web omnibox provider
+    is disabled.
+  </summary>
+</histogram>
+
 <histogram name="Omnibox.PhysicalWebProviderMatches">
   <owner>cco3@chromium.org</owner>
   <owner>mattreynolds@chromium.org</owner>
@@ -43093,13 +43107,51 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 </histogram>
 
 <histogram name="Omnibox.SuggestionUsed.NearbyURLCount" units="URLs">
-  <owner>cco3@chromium.org</owner>
-  <owner>mattreynolds@chromium.org</owner>
-  <owner>mmocny@chromium.org</owner>
+  <obsolete>
+    Deprecated in M58, replaced with
+    Omnibox.SuggestionUsed.NearbyURLCount.AtFocus and
+    Omnibox.SuggestionUsed.NearbyURLCount.AtMatchCreation.
+  </obsolete>
   <summary>
     The number of nearby Physical Web URLs when the user focused the omnibox.
     Recorded when the user accepts an omnibox suggestion, regardless of whether
     the suggestion came from PhysicalWebProvider. Capped at 50.
+
+    In M57, the values recorded by this histogram were determined to be bugged.
+    It's believed that it was recording uninitialized values due to a corner
+    case on Android that allows an omnibox suggestion to be selected without
+    first focusing the omnibox. In addition to the new histograms,
+    Omnibox.PhysicalWebProvider.SuggestionUsedWithoutOmniboxFocus was added to
+    detect this case. https://crbug.com/691059
+  </summary>
+</histogram>
+
+<histogram name="Omnibox.SuggestionUsed.NearbyURLCount.AtFocus" units="URLs">
+  <owner>cco3@chromium.org</owner>
+  <owner>mattreynolds@chromium.org</owner>
+  <owner>mmocny@chromium.org</owner>
+  <summary>
+    The number of nearby Physical Web URLs when Physical Web Provider was last
+    focused (i.e., the start of the current session). Recorded when the user
+    accepts an omnibox suggestion, regardless of whether the suggestion came
+    from PhysicalWebProvider. Capped at 50.
+
+    Does not record if the omnibox was not focused during the current session.
+    Omnibox.PhysicalWebProvider.SuggestionUsedWithoutOmniboxFocus records true
+    when we hit this case.
+  </summary>
+</histogram>
+
+<histogram name="Omnibox.SuggestionUsed.NearbyURLCount.AtMatchCreation"
+    units="URLs">
+  <owner>cco3@chromium.org</owner>
+  <owner>mattreynolds@chromium.org</owner>
+  <owner>mmocny@chromium.org</owner>
+  <summary>
+    The number of nearby Physical Web URLs when Physical Web Provider last
+    constructed matches. Recorded when the user accepts an omnibox suggestion,
+    regardless of whether the suggestion came from PhysicalWebProvider. Capped
+    at 50.
   </summary>
 </histogram>