Persist Directory to disk when the app is backgrounded.

chrome/browser/sync/profile_sync_service_android.cc

Index: chrome/browser/sync/profile_sync_service_android.cc
diff --git a/chrome/browser/sync/profile_sync_service_android.cc b/chrome/browser/sync/profile_sync_service_android.cc
index 567297cc9c73ec7f3cee65a6117d4c43ed2b2733..d6015654393de8643927fadd5983a1ca8d5c2b7b 100644
--- a/chrome/browser/sync/profile_sync_service_android.cc
+++ b/chrome/browser/sync/profile_sync_service_android.cc
@@ -181,6 +181,11 @@ void ProfileSyncServiceAndroid::SignOutSync(JNIEnv* env, jobject) {
   sync_prefs_->SetStartSuppressed(false);
 }
 
+void ProfileSyncServiceAndroid::FlushDirectory(JNIEnv* env, jobject) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  sync_service_->FlushDirectory();
+}
+
 ScopedJavaLocalRef<jstring> ProfileSyncServiceAndroid::QuerySyncStatusSummary(
     JNIEnv* env, jobject) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));