Persist Directory to disk when the app is backgrounded.

chrome/android/java/src/org/chromium/chrome/browser/sync/ProfileSyncService.java

 // Copyright 2013 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.
 
 package org.chromium.chrome.browser.sync;
 
+import android.app.Activity;
 import android.content.Context;
 import android.util.Log;
 
 import com.google.common.base.Joiner;
 
+import org.chromium.base.ActivityState;
+import org.chromium.base.ApplicationStatus;
+import org.chromium.base.ApplicationStatus.ActivityStateListener;
 import org.chromium.base.CalledByNative;
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.chrome.browser.identity.UniqueIdentificationGenerator;
 import org.chromium.sync.internal_api.pub.SyncDecryptionPassphraseType;
 import org.chromium.sync.internal_api.pub.base.ModelType;
 
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 import java.util.SortedSet;
 import java.util.TreeSet;
 import java.util.concurrent.CopyOnWriteArrayList;
 
 /**
  * Android wrapper of the ProfileSyncService which provides access from the Java layer.
  * <p/>
  * This class mostly wraps native classes, but it make a few business logic decisions, both in Java
  * and in native.
  * <p/>
  * Only usable from the UI thread as the native ProfileSyncService requires its access to be in the
  * UI thread.
  * <p/>
  * See chrome/browser/sync/profile_sync_service.h for more details.
  */
 public class ProfileSyncService {
 
+    /**
+     * Listener for sync status changes.
+     */
     public interface SyncStateChangedListener {
         // Invoked when the underlying sync status has changed.
         public void syncStateChanged();
     }
 
     private static final String TAG = "ProfileSyncService";
 
     @VisibleForTesting
     public static final String SESSION_TAG_PREFIX = "session_sync";
 
@@ skipping 30 matching lines @@
      */
     private ProfileSyncService(Context context) {
         ThreadUtils.assertOnUiThread();
         // We should store the application context, as we outlive any activity which may create us.
         mContext = context.getApplicationContext();
 
         // This may cause us to create ProfileSyncService even if sync has not
         // been set up, but ProfileSyncService::Startup() won't be called until
         // credentials are available.
         mNativeProfileSyncServiceAndroid = nativeInit();
+
+        // When the application gets paused, tell sync to flush the directory to disk.
+        ApplicationStatus.registerStateListenerForAllActivities(new ActivityStateListener() {
+          @Override
+          public void onActivityStateChange(Activity activity, int newState) {
+            if (newState == ActivityState.PAUSED) {
+              flushDirectory();
+            }
+          }
+        });
     }
 
     @CalledByNative
     private static long getProfileSyncServiceAndroid(Context context) {
         return get(context).mNativeProfileSyncServiceAndroid;
     }
 
     /**
      * If we are currently in the process of setting up sync, this method clears the
      * sync setup in progress flag.
@@ skipping 397 matching lines @@
     }
 
     /**
      * Stops the sync engine.
      */
     public void disableSync() {
         nativeDisableSync(mNativeProfileSyncServiceAndroid);
     }
 
     /**
+     * Flushes the sync directory.
+     */
+    public void flushDirectory() {
+        nativeFlushDirectory(mNativeProfileSyncServiceAndroid);
+    }
+
+    /**
      * Returns the time when the last sync cycle was completed.
      *
      * @return The difference measured in microseconds, between last sync cycle completion time
      * and 1 January 1970 00:00:00 UTC.
      */
     @VisibleForTesting
     public long getLastSyncedTimeForTest() {
         return nativeGetLastSyncedTimeForTest(mNativeProfileSyncServiceAndroid);
     }
 
@@ skipping 21 matching lines @@
     }
 
     // Native methods
     private native void nativeNudgeSyncer(
             long nativeProfileSyncServiceAndroid, int objectSource, String objectId, long version,
             String payload);
     private native void nativeNudgeSyncerForAllTypes(long nativeProfileSyncServiceAndroid);
     private native long nativeInit();
     private native void nativeEnableSync(long nativeProfileSyncServiceAndroid);
     private native void nativeDisableSync(long nativeProfileSyncServiceAndroid);
+    private native void nativeFlushDirectory(long nativeProfileSyncServiceAndroid);
     private native void nativeSignInSync(long nativeProfileSyncServiceAndroid);
     private native void nativeSignOutSync(long nativeProfileSyncServiceAndroid);
     private native boolean nativeSetSyncSessionsId(
             long nativeProfileSyncServiceAndroid, String tag);
     private native String nativeQuerySyncStatusSummary(long nativeProfileSyncServiceAndroid);
     private native int nativeGetAuthError(long nativeProfileSyncServiceAndroid);
     private native boolean nativeIsSyncInitialized(long nativeProfileSyncServiceAndroid);
     private native boolean nativeIsFirstSetupInProgress(long nativeProfileSyncServiceAndroid);
     private native boolean nativeIsEncryptEverythingEnabled(long nativeProfileSyncServiceAndroid);
     private native void nativeEnableEncryptEverything(long nativeProfileSyncServiceAndroid);
@@ skipping 26 matching lines @@
     private native void nativeSetSyncSetupCompleted(long nativeProfileSyncServiceAndroid);
     private native boolean nativeHasSyncSetupCompleted(long nativeProfileSyncServiceAndroid);
     private native boolean nativeIsStartSuppressed(long nativeProfileSyncServiceAndroid);
     private native boolean nativeHasKeepEverythingSynced(long nativeProfileSyncServiceAndroid);
     private native boolean nativeHasUnrecoverableError(long nativeProfileSyncServiceAndroid);
     private native String nativeGetAboutInfoForTest(long nativeProfileSyncServiceAndroid);
     private native long nativeGetLastSyncedTimeForTest(long nativeProfileSyncServiceAndroid);
     private native void nativeOverrideNetworkResourcesForTest(
             long nativeProfileSyncServiceAndroid, long networkResources);
 }