PaymentHandler: Implement requestPermission().

WATCHLISTS

 # Copyright (c) 2012 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.
 
 # Watchlist Rules
 # Refer: http://dev.chromium.org/developers/contributing-code/watchlists
 
 # IMPORTANT: The regular expression filepath is tested against each path using
 # re.search, so it is not usually necessary to add .*.
 
@@ skipping 869 matching lines @@
                   '|chrome/browser/ui/passwords'\
                   '|chrome/browser/ui/views/passwords'\
                   '|chrome/test/data/password'\
                   '|components/autofill.*password'
                   '|components/password_'\
                   '|^ios/chrome/browser/passwords'\
     },
     'payments': {
       'filepath': 'chrome/android/java/src/org/chromium/chrome/browser/payments'\
                   '|chrome/android/javatests/src/org/chromium/chrome/browser/payments'\
+                  '|chrome/browser/payments'\
                   '|chrome/test/data/payments'\
                   '|components/payments'\
                   '|third_party/WebKit/LayoutTests/payments/'\
                   '|third_party/WebKit/Source/modules/payments'\
                   '|ios/web/payments/'\
                   '|ios/web/public/payments/'\
                   '|ios/chrome/browser/payments/'
     },
     'payments_ios': {
       'filepath': 'ios/web/payments/'\
@@ skipping 1375 matching lines @@
                          'msramek+watch@chromium.org',
                          'raymes+watch@chromium.org'],
     'windows_sandboxing': ['pennymac+watch@chromium.org',
                            'wfh+watch@chromium.org'],
     'x11': ['derat+watch@chromium.org',
             'sadrul@chromium.org',
             'yusukes+watch@chromium.org'],
     'zoom': ['wjmaclean@chromium.org'],
   },
 }