Fix history importing by delaying DownloadManager creation.

content/browser/download/download_id_factory.cc

Index: content/browser/download/download_id_factory.cc
diff --git a/content/browser/download/download_id_factory.cc b/content/browser/download/download_id_factory.cc
new file mode 100644
index 0000000000000000000000000000000000000000..6b0797f88c4a9f559c60b96f147082cca8a48ef1
--- /dev/null
+++ b/content/browser/download/download_id_factory.cc
@@ -0,0 +1,17 @@
+// Copyright (c) 2011 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/download/download_id_factory.h"
+
+#include "content/browser/download/download_id.h"
+
+DownloadIdFactory::DownloadIdFactory(DownloadId::Domain domain)
+  : domain_(domain),
+    next_id_(0) {
+}
+
+DownloadId DownloadIdFactory::GetNextId() {
+  base::AutoLock lock(lock_);
+  return DownloadId(domain_, next_id_++);

[Randy Smith (Not in Mondays), 2011/10/28 13:35:44]

Nit's nit: For complex data types (i.e. most iterators) defaulting to
pre-increment is better because it doesn't involve a copy.  So I think it's
useful to be in the habit of using pre-increment when it doesn't matter.  This
is just FYI; you're welcome to leave this code however you'd like.

[benjhayden, 2011/10/28 14:37:55]

Yeah, but I'd rather initialize the counter to the first value that will be
returned for clarity. If this changes to an ASN then I'll change it to
pre-increment and document the -1.

+}