Fix number of buckets in Tabs.ScrubDistance UMA histogram.

chrome/browser/ui/views/ash/tab_scrubber.cc

Index: chrome/browser/ui/views/ash/tab_scrubber.cc
diff --git a/chrome/browser/ui/views/ash/tab_scrubber.cc b/chrome/browser/ui/views/ash/tab_scrubber.cc
index 49ef35aca62a7f0dac0a24198e480fb443679fdb..cfff2b8b990288ef111fd047c1f60047be88c4fd 100644
--- a/chrome/browser/ui/views/ash/tab_scrubber.cc
+++ b/chrome/browser/ui/views/ash/tab_scrubber.cc
@@ -274,7 +274,7 @@ void TabScrubber::FinishScrub(bool activate) {
       int distance =
           std::abs(
               highlighted_tab_ - browser_->tab_strip_model()->active_index());
-      UMA_HISTOGRAM_CUSTOM_COUNTS("Tabs.ScrubDistance", distance, 0, 20, 20);
+      UMA_HISTOGRAM_CUSTOM_COUNTS("Tabs.ScrubDistance", distance, 0, 20, 21);
       browser_->tab_strip_model()->ActivateTabAt(highlighted_tab_, true);
     }
     tab_strip->RemoveObserver(this);