[Payments] Fix the Payment Request histogram check failure in tests.

chrome/android/java/src/org/chromium/chrome/browser/payments/PaymentRequestJourneyLogger.java

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chrome.browser.payments;
 
 import org.chromium.base.metrics.RecordHistogram;
 
 /**
  * A class used to record journey metrics for the Payment Request feature.
  */
 public class PaymentRequestJourneyLogger {
     public static final int SECTION_CONTACT_INFO = 0;
     public static final int SECTION_CREDIT_CARDS = 1;
     public static final int SECTION_SHIPPING_ADDRESS = 2;
     public static final int SECTION_MAX = 3;
 
-    private static final int MIN_EXPECTED_SAMPLE = 0;
+    // The min has to be set to 1 even though we can log 0.

[please use gerrit instead, 2016/10/26 22:01:14]

Please explain why min has to be 1 and why can log 0. If there's a bug about
this, you can link to it instead.

[sebsg, 2016/10/26 23:42:03]

Please tell me if this is more clear. I'm making a CL to enforce this.

+    private static final int MIN_EXPECTED_SAMPLE = 1;
     private static final int MAX_EXPECTED_SAMPLE = 49;
     private static final int NUMBER_BUCKETS = 50;
 
     private static class SectionStats {
         private int mNumberSuggestionsShown;
         private int mNumberSelectionChanges;
         private int mNumberSelectionEdits;
         private int mNumberSelectionAdds;
         private boolean mIsRequested;
     }
@@ skipping 89 matching lines @@
                         Math.min(mSections[i].mNumberSelectionEdits, MAX_EXPECTED_SAMPLE),
                         MIN_EXPECTED_SAMPLE, MAX_EXPECTED_SAMPLE, NUMBER_BUCKETS);
                 RecordHistogram.recordCustomCountHistogram(
                         "PaymentRequest.NumberOfSuggestionsShown." + nameSuffix,
                         Math.min(mSections[i].mNumberSuggestionsShown, MAX_EXPECTED_SAMPLE),
                         MIN_EXPECTED_SAMPLE, MAX_EXPECTED_SAMPLE, NUMBER_BUCKETS);
             }
         }
     }
 }