[Feed] Fix crash when clearing cached data after being disabled

The Feed can be disabled and destroyed without warning, meaning
calls to FeedProcessScopeFactory#getFoo() can return null. This CL
guards against that for FeedLifecycleBridge

Bug: 902123
Change-Id: Iff4fb6eb1c1e19358637159558d1983e774a42a2
Reviewed-on: https://chromium-review.googlesource.com/c/1327550
Commit-Queue: Patrick Noland <pnoland@chromium.org>
Reviewed-by: Sky Malice <skym@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607355}

chrome/android/feed/core/java/src/org/chromium/chrome/browser/feed/FeedLifecycleBridge.java

@@ -4,6 +4,7 @@
 
 package org.chromium.chrome.browser.feed;
 
+import org.chromium.base.VisibleForTesting;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
 import org.chromium.chrome.browser.profiles.Profile;
@@ -34,16 +35,22 @@ public class FeedLifecycleBridge {
         mNativeBridge = 0;
     }
 
+    @VisibleForTesting
     @CalledByNative
-    private static void onCachedDataCleared() {
-        FeedProcessScopeFactory.getFeedAppLifecycle().onCachedDataCleared();
+    static void onCachedDataCleared() {
+        FeedAppLifecycle lifecycle = FeedProcessScopeFactory.getFeedAppLifecycle();
+        if (lifecycle != null) {
+            lifecycle.onCachedDataCleared();
+        }
     }
 
-    // This would ordinarily be non-static, but there's no instance state, so for simplicity it's
-    // isomorphic to onCachedDataCleared.
+    @VisibleForTesting
     @CalledByNative
-    private static void onHistoryDeleted() {
-        FeedProcessScopeFactory.getFeedAppLifecycle().onHistoryDeleted();
+    static void onHistoryDeleted() {
+        FeedAppLifecycle lifecycle = FeedProcessScopeFactory.getFeedAppLifecycle();
+        if (lifecycle != null) {
+            lifecycle.onHistoryDeleted();
+        }
     }
 
     private native long nativeInit(Profile profile);

chrome/android/javatests/src/org/chromium/chrome/browser/feed/FeedAppLifecycleTest.java

@@ -42,6 +42,8 @@ import org.chromium.chrome.browser.feed.FeedAppLifecycle.AppLifecycleEvent;
 import org.chromium.chrome.browser.init.ChromeBrowserInitializer;
 import org.chromium.chrome.browser.multiwindow.MultiWindowTestHelper;
 import org.chromium.chrome.browser.multiwindow.MultiWindowUtils;
+import org.chromium.chrome.browser.preferences.Pref;
+import org.chromium.chrome.browser.preferences.PrefServiceBridge;
 import org.chromium.chrome.browser.profiles.Profile;
 import org.chromium.chrome.test.ChromeJUnit4ClassRunner;
 import org.chromium.chrome.test.ChromeTabbedActivityTestRule;
@@ -61,8 +63,6 @@ public class FeedAppLifecycleTest {
     @Rule
     public ChromeTabbedActivityTestRule mActivityTestRule = new ChromeTabbedActivityTestRule();
     @Mock
-    private FeedLifecycleBridge mLifecycleBridge;
-    @Mock
     private FeedScheduler mFeedScheduler;
     @Mock
     private NetworkClient mNetworkClient;
@@ -74,6 +74,7 @@ public class FeedAppLifecycleTest {
     private Map<String, Boolean> mMockFeatureList;
     private ChromeTabbedActivity mActivity;
     private FeedAppLifecycle mAppLifecycle;
+    private FeedLifecycleBridge mLifecycleBridge;
     private final String mHistogramAppLifecycleEvents =
             "ContentSuggestions.Feed.AppLifecycle.Events";
 
@@ -89,14 +90,15 @@ public class FeedAppLifecycleTest {
             } catch (ProcessInitException e) {
                 Assert.fail("Native initialization failed");
             }
-
+            Profile profile = Profile.getLastUsedProfile().getOriginalProfile();
+            mLifecycleBridge = new FeedLifecycleBridge(profile);
             mAppLifecycle =
                     new FeedAppLifecycle(mAppLifecycleListener, mLifecycleBridge, mFeedScheduler);
             FeedProcessScopeFactory.createFeedProcessScopeForTesting(mFeedScheduler, mNetworkClient,
                     mOfflineIndicator, mAppLifecycle,
                     new FeedAppLifecycleListener(
                             new com.google.android.libraries.feed.api.common.ThreadUtils()),
-                    new FeedLoggingBridge(Profile.getLastUsedProfile().getOriginalProfile()));
+                    new FeedLoggingBridge(profile));
         });
 
         mActivityTestRule.startMainActivityOnBlankPage();
@@ -246,6 +248,18 @@ public class FeedAppLifecycleTest {
         verify(mFeedScheduler, times(2)).onForegrounded();
     }
 
+    @Test
+    @SmallTest
+    @Feature({"InterestFeedContentSuggestions"})
+    public void clear_data_after_disabling_does_not_crash() {
+        ThreadUtils.runOnUiThreadBlocking(() -> {
+            FeedProcessScopeFactory.clearFeedProcessScopeForTesting();
+            PrefServiceBridge.getInstance().setBoolean(Pref.NTP_ARTICLES_SECTION_ENABLED, false);
+            FeedLifecycleBridge.onCachedDataCleared();
+            FeedLifecycleBridge.onHistoryDeleted();
+        });
+    }
+
     private void signalActivityStart(Activity activity)
             throws InterruptedException, TimeoutException {
         signalActivityState(activity, ActivityState.STARTED);