Add the IndexedDBActiveBlobRegistry, currently unused, to enable future blob

content/browser/indexed_db/indexed_db_backing_store_unittest.cc

Index: content/browser/indexed_db/indexed_db_backing_store_unittest.cc
diff --git a/content/browser/indexed_db/indexed_db_backing_store_unittest.cc b/content/browser/indexed_db/indexed_db_backing_store_unittest.cc
index 4d6beb30c4abcd740e99677aa3176b2226ec91bf..3ee08fbe95af0ceaff41c32e3df311355ec980b7 100644
--- a/content/browser/indexed_db/indexed_db_backing_store_unittest.cc
+++ b/content/browser/indexed_db/indexed_db_backing_store_unittest.cc
@@ -23,7 +23,8 @@ class IndexedDBBackingStoreTest : public testing::Test {
   IndexedDBBackingStoreTest() {}
   virtual void SetUp() {
     const GURL origin("http://localhost:81");
-    backing_store_ = IndexedDBBackingStore::OpenInMemory(origin);
+    backing_store_ =
+        IndexedDBBackingStore::OpenInMemory(origin, NULL /* task_runner */);
 
     // useful keys and values during tests
     m_value1 = IndexedDBValue("value1", std::vector<IndexedDBBlobInfo>());