Let IndexedDBContextImpl create its own task runner

content/browser/indexed_db/indexed_db_dispatcher_host_unittest.cc

 // Copyright 2017 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.
 
 #include "content/browser/indexed_db/indexed_db_dispatcher_host.h"
 
 #include "base/barrier_closure.h"
 #include "base/callback.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/memory/ptr_util.h"
@@ skipping 130 matching lines @@
         special_storage_policy_(new MockSpecialStoragePolicy()),
         quota_manager_(new MockQuotaManager(false,
                                             browser_context_.GetPath(),
                                             io_task_runner_,
                                             idb_task_runner_,
                                             special_storage_policy_)),
         quota_manager_proxy_(quota_manager_->proxy()),
         context_impl_(
             new IndexedDBContextImpl(CreateAndReturnTempDir(&temp_dir_),
                                      special_storage_policy_.get(),
-                                     quota_manager_proxy_.get(),
-                                     idb_task_runner_.get())),
+                                     quota_manager_proxy_.get())),
         blob_storage_(ChromeBlobStorageContext::GetFor(&browser_context_)),
         host_(new IndexedDBDispatcherHost(kFakeProcessId,
                                           request_context_getter_.get(),
                                           context_impl_.get(),
                                           blob_storage_.get())) {
     quota_manager_->SetQuota(GURL(kOrigin), storage::kStorageTypePersistent,
                              kTemporaryQuota);
     quota_manager_->SetQuota(GURL(kOrigin), storage::kStorageTypeTemporary,
                              kPersistantQuota);
+    context_impl_->SetTaskRunnerForTesting(idb_task_runner_);
   }
 
   void TearDown() override {
     host_.reset();
     // In order for idb_thread_.Stop() to not cause thread/taskrunner checking
     // errors, the handles must be deref'd before we join threads. This ensures
     // classes that require destruction on the idb thread can be destructed
     // correctly before scheduling on the the idb thread task runner turns into
     // a no-op after thread join.
     blob_storage_ = nullptr;
@@ skipping 264 matching lines @@
                              content::IndexedDBKey(base::UTF8ToUTF16("hello")),
                              blink::kWebIDBPutModeAddOnly,
                              std::vector<content::IndexedDBIndexKeys>(),
                              put_callbacks->CreateInterfacePtrAndBind());
     connection.database->Commit(kTransactionId);
     loop.Run();
   }
 }
 
 }  // namespace content