[Android O] Only delete legacy notification channels on upgrade

chrome/android/java_sources.gni

 # 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.
 
 chrome_java_sources = [
   "java/src/com/google/android/apps/chrome/appwidget/bookmarks/BookmarkThumbnailWidgetProvider.java",
   "java/src/org/chromium/chrome/browser/ActivityTabTaskDescriptionHelper.java",
   "java/src/org/chromium/chrome/browser/ActivityTaskDescriptionIconGenerator.java",
   "java/src/org/chromium/chrome/browser/AfterStartupTaskUtils.java",
   "java/src/org/chromium/chrome/browser/AppIndexingUtil.java",
@@ skipping 1637 matching lines @@
   "junit/src/org/chromium/chrome/browser/media/router/cast/TestUtils.java",
   "junit/src/org/chromium/chrome/browser/media/ui/MediaImageManagerTest.java",
   "junit/src/org/chromium/chrome/browser/media/ui/MediaNotificationButtonComputationTest.java",
   "junit/src/org/chromium/chrome/browser/media/ui/MediaNotificationTestShadowNotificationManager.java",
   "junit/src/org/chromium/chrome/browser/media/ui/MediaNotificationTestShadowResources.java",
   "junit/src/org/chromium/chrome/browser/media/ui/MediaNotificationManagerTestBase.java",
   "junit/src/org/chromium/chrome/browser/media/ui/MediaNotificationManagerServiceActionsTest.java",
   "junit/src/org/chromium/chrome/browser/media/ui/MediaNotificationManagerServiceLifecycleTest.java",
   "junit/src/org/chromium/chrome/browser/media/ui/MediaNotificationManagerNotificationTest.java",
   "junit/src/org/chromium/chrome/browser/metrics/VariationsSessionTest.java",
+  "junit/src/org/chromium/chrome/browser/notifications/ChannelDefinitionsTest.java",
   "junit/src/org/chromium/chrome/browser/notifications/ChannelsInitializerTest.java",
   "junit/src/org/chromium/chrome/browser/notifications/ChannelsUpdaterTest.java",
   "junit/src/org/chromium/chrome/browser/notifications/NotificationPlatformBridgeUnitTest.java",
   "junit/src/org/chromium/chrome/browser/ntp/NativePageFactoryTest.java",
   "junit/src/org/chromium/chrome/browser/ntp/TitleUtilTest.java",
   "junit/src/org/chromium/chrome/browser/ntp/cards/ContentSuggestionsUnitTestUtils.java",
   "junit/src/org/chromium/chrome/browser/ntp/cards/FakeOfflinePageBridge.java",
   "junit/src/org/chromium/chrome/browser/ntp/cards/InnerNodeTest.java",
   "junit/src/org/chromium/chrome/browser/ntp/cards/NewTabPageAdapterTest.java",
   "junit/src/org/chromium/chrome/browser/ntp/cards/SuggestionsCategoryInfoTest.java",
@@ skipping 45 matching lines @@
   "sync_shell/javatests/src/org/chromium/chrome/browser/sync/SyncTestBase.java",
   "sync_shell/javatests/src/org/chromium/chrome/browser/sync/TypedUrlsTest.java",
   "sync_shell/javatests/src/org/chromium/chrome/browser/sync/ui/PassphraseTypeDialogFragmentTest.java",
 ]
 
 # Only used for testing, should not be shipped to end users.
 if (!is_official_build) {
   chrome_java_sources += [ "java/src/org/chromium/chrome/browser/offlinepages/evaluation/OfflinePageEvaluationBridge.java" ]
   chrome_test_java_sources += [ "javatests/src/org/chromium/chrome/browser/offlinepages/OfflinePageSavePageLaterEvaluationTest.java" ]
 }