[FCM] Adding the ability to change the subscription laziness mode.

This CL adds the ability to change a subscription from lazy to unlazy.

Bug: 882887
Change-Id: I0dc68442feb2ac460b82896ee424c806f6613041
Reviewed-on: https://chromium-review.googlesource.com/c/1296603
Commit-Queue: Mohamed Amir Yosef <mamir@chromium.org>
Reviewed-by: Peter Beverloo <peter@chromium.org>
Reviewed-by: Peter Conn <peconn@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610175}

components/gcm_driver/android/java/src/org/chromium/components/gcm_driver/LazySubscriptionsManager.java

@@ -85,18 +85,26 @@ public class LazySubscriptionsManager {
      * Stores the information about lazy subscriptions in SharedPreferences.
      */
     public static void storeLazinessInformation(final String subscriptionId, boolean isLazy) {
-        if (isLazy) {
-            Context context = ContextUtils.getApplicationContext();
-            SharedPreferences sharedPrefs =
-                    context.getSharedPreferences(PREF_PACKAGE, Context.MODE_PRIVATE);
-            Set<String> lazyIds = new HashSet<>(
-                    sharedPrefs.getStringSet(FCM_LAZY_SUBSCRIPTIONS, Collections.emptySet()));
+        boolean isAlreadyLazy = isSubscriptionLazy(subscriptionId);
+        if (isAlreadyLazy == isLazy) {
+            return;
+        }
+        if (isAlreadyLazy) {
+            // Switching from lazy to unlazy.
+            // Delete any queued messages.
+            deletePersistedMessagesForSubscriptionId(subscriptionId);
+        }
+        Context context = ContextUtils.getApplicationContext();
+        SharedPreferences sharedPrefs =
+                context.getSharedPreferences(PREF_PACKAGE, Context.MODE_PRIVATE);
+        Set<String> lazyIds = new HashSet<>(
+                sharedPrefs.getStringSet(FCM_LAZY_SUBSCRIPTIONS, Collections.emptySet()));
+        if (isAlreadyLazy) {
+            lazyIds.remove(subscriptionId);
+        } else { // Switching from unlazy to lazy.
             lazyIds.add(subscriptionId);
-            sharedPrefs.edit().putStringSet(FCM_LAZY_SUBSCRIPTIONS, lazyIds).apply();
         }
-        // TODO(https://crbug.com/882887): Check if that
-        // subscription was marked lazy before and handle the change
-        // accordingly.
+        sharedPrefs.edit().putStringSet(FCM_LAZY_SUBSCRIPTIONS, lazyIds).apply();
     }
 
     /**

components/gcm_driver/android/junit/src/org/chromium/components/gcm_driver/LazySubscriptionsManagerTest.java

@@ -16,6 +16,7 @@ import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.robolectric.annotation.Config;
 
+import org.chromium.base.metrics.CachedMetrics;
 import org.chromium.base.metrics.RecordHistogram;
 import org.chromium.base.metrics.test.ShadowRecordHistogram;
 import org.chromium.base.test.BaseRobolectricTestRunner;
@@ -30,6 +31,8 @@ import java.util.Set;
 public class LazySubscriptionsManagerTest {
     @Before
     public void setUp() {
+        // This commits and clears any cached metrics.
+        CachedMetrics.commitCachedMetrics();
         ShadowRecordHistogram.reset();
     }
 
@@ -77,6 +80,40 @@ public class LazySubscriptionsManagerTest {
         assertFalse(LazySubscriptionsManager.isSubscriptionLazy(subscriptionId));
     }
 
+    /**
+     * Tests that switching from lazy to unlazy should leave no queued messages behind.
+     */
+    @Test
+    public void testSwitchingFromLazyToUnlazy() {
+        final String subscriptionId = "subscription_id";
+        LazySubscriptionsManager.storeLazinessInformation(subscriptionId, true);
+
+        Bundle extras = new Bundle();
+        extras.putString("subtype", "MyAppId");
+        extras.putString("collapse_key", "CollapseKey");
+        GCMMessage message = new GCMMessage("MySenderId", extras);
+
+        LazySubscriptionsManager.persistMessage(subscriptionId, message);
+        assertEquals(1, LazySubscriptionsManager.readMessages(subscriptionId).length);
+
+        LazySubscriptionsManager.storeLazinessInformation(subscriptionId, false);
+        assertEquals(0, LazySubscriptionsManager.readMessages(subscriptionId).length);
+    }
+
+    /**
+     * Tests that switching from lazy to unlazy and back to lazy.
+     */
+    @Test
+    public void testSwitchingFromLazyToUnlazyAndBackToLazy() {
+        final String subscriptionId = "subscription_id";
+        LazySubscriptionsManager.storeLazinessInformation(subscriptionId, true);
+        assertTrue(LazySubscriptionsManager.isSubscriptionLazy(subscriptionId));
+        LazySubscriptionsManager.storeLazinessInformation(subscriptionId, false);
+        assertFalse(LazySubscriptionsManager.isSubscriptionLazy(subscriptionId));
+        LazySubscriptionsManager.storeLazinessInformation(subscriptionId, true);
+        assertTrue(LazySubscriptionsManager.isSubscriptionLazy(subscriptionId));
+    }
+
     @Test
     public void testGetLazySubscriptionIds() {
         final String subscriptionId1 = "subscription_id1";