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 7bfaff74186572a29ca6c1200ceca87dd1bbb484..8683848e476ff2b640d1c9adc19a1f4732c77434 100644
--- a/chrome/browser/sync/profile_sync_service_android.cc
+++ b/chrome/browser/sync/profile_sync_service_android.cc
@@ -141,6 +141,11 @@ 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));