[Android O] Initialize channels on first launch/upgrade

chrome/android/junit/src/org/chromium/chrome/browser/notifications/ChannelsInitializerTest.java

Index: chrome/android/junit/src/org/chromium/chrome/browser/notifications/ChannelsInitializerTest.java
diff --git a/chrome/android/junit/src/org/chromium/chrome/browser/notifications/ChannelsInitializerTest.java b/chrome/android/junit/src/org/chromium/chrome/browser/notifications/ChannelsInitializerTest.java
index 7628147bc771f26729c48d08a07c5aeffc605b07..f36ae9f84e59f963d05b4c7c3f3c836b7b2db03c 100644
--- a/chrome/android/junit/src/org/chromium/chrome/browser/notifications/ChannelsInitializerTest.java
+++ b/chrome/android/junit/src/org/chromium/chrome/browser/notifications/ChannelsInitializerTest.java
@@ -4,6 +4,7 @@
 
 package org.chromium.chrome.browser.notifications;
 
+import static org.hamcrest.Matchers.greaterThan;
 import static org.hamcrest.Matchers.is;
 import static org.junit.Assert.assertThat;
 
@@ -70,4 +71,10 @@ public class ChannelsInitializerTest {
         assertThat(group.mNameResId,
                 is(org.chromium.chrome.R.string.notification_category_group_general));
     }
+
+    @Test
+    public void testInitializeStartupChannels() throws Exception {
+        mChannelsInitializer.initializeStartupChannels();
+        assertThat(mMockNotificationManager.getChannels().size(), is(greaterThan(0)));
+    }
 }