Indexed DB: Remove transaction throttle

content/browser/indexed_db/indexed_db_database.cc

 // Copyright (c) 2013 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_database.h"
 
 #include <math.h>
 #include <limits>
 #include <set>
 #include <utility>
@@ skipping 1654 matching lines @@
   IDB_TRACE1("IndexedDBDatabase::CreateTransaction", "txn.id", transaction_id);
   DCHECK(connections_.count(connection));
   DCHECK(transactions_.find(transaction_id) == transactions_.end());
   if (transactions_.find(transaction_id) != transactions_.end())
     return;
 
   UMA_HISTOGRAM_COUNTS_1000(
       "WebCore.IndexedDB.Database.OutstandingTransactionCount",
       transactions_.size());
 
-  // Throttle transaction creation so that a renderer in a tight loop can't
-  // cause browser memory to grow unbounded by creating transactions faster
-  // than they can be processed.
-  const size_t kMaxTransactionCount = 256;
-  if (transactions_.size() >= kMaxTransactionCount) {
-    connection->callbacks()->OnAbort(
-        transaction_id, IndexedDBDatabaseError(
-                            blink::WebIDBDatabaseExceptionUnknownError,
-                            "Internal error: Too many transactions queued."));
-    return;
-  }
-
   // The transaction will add itself to this database's coordinator, which
   // manages the lifetime of the object.
   TransactionCreated(IndexedDBClassFactory::Get()->CreateIndexedDBTransaction(
       transaction_id, connection->callbacks(),
       std::set<int64_t>(object_store_ids.begin(), object_store_ids.end()), mode,
       this, new IndexedDBBackingStore::Transaction(backing_store_.get())));
 }
 
 void IndexedDBDatabase::TransactionCreated(IndexedDBTransaction* transaction) {
   transactions_[transaction->id()] = transaction;
@@ skipping 283 matching lines @@
     const base::string16& previous_version,
     int64_t previous_int_version,
     IndexedDBTransaction* transaction) {
   DCHECK(!transaction);
   IDB_TRACE("IndexedDBDatabase::VersionChangeAbortOperation");
   metadata_.version = previous_version;
   metadata_.int_version = previous_int_version;
 }
 
 }  // namespace content