Do updateWorkspaceScreenOrder inside a single transaction.

The workspacescreens table is updated in LauncherModel.updateWorkspaceScreenOrder
and that the operation to remove all screens, then reinsert the new list of
screens in not inside a single transaction, so if the app is updating or
crashes between ContentResolver.delete and ContentResolver.bulkInsert then
the data will be lost. This CL makes it all happen inside 1 transaction.

Bug: 12523285
Change-Id: I409dbc9f48fa9c8bd4bf3b1453204a4daac1689a
diff --git a/src/com/android/launcher3/LauncherProvider.java b/src/com/android/launcher3/LauncherProvider.java
index cec9167..a69f423 100644
--- a/src/com/android/launcher3/LauncherProvider.java
+++ b/src/com/android/launcher3/LauncherProvider.java
@@ -22,11 +22,14 @@
 import android.appwidget.AppWidgetProviderInfo;
 import android.content.ComponentName;
 import android.content.ContentProvider;
+import android.content.ContentProviderOperation;
+import android.content.ContentProviderResult;
 import android.content.ContentResolver;
 import android.content.ContentUris;
 import android.content.ContentValues;
 import android.content.Context;
 import android.content.Intent;
+import android.content.OperationApplicationException;
 import android.content.SharedPreferences;
 import android.content.pm.ActivityInfo;
 import android.content.pm.PackageManager;
@@ -194,6 +197,20 @@
     }
 
     @Override
+    public ContentProviderResult[] applyBatch(ArrayList<ContentProviderOperation> operations)
+            throws OperationApplicationException {
+        SQLiteDatabase db = mOpenHelper.getWritableDatabase();
+        db.beginTransaction();
+        try {
+            ContentProviderResult[] result =  super.applyBatch(operations);
+            db.setTransactionSuccessful();
+            return result;
+        } finally {
+            db.endTransaction();
+        }
+    }
+
+    @Override
     public int delete(Uri uri, String selection, String[] selectionArgs) {
         SqlArguments args = new SqlArguments(uri, selection, selectionArgs);