Introduce HostID and de-couple Extensions from "script injection System" [browser side]

extensions/common/consumer.cc

Index: extensions/common/consumer.cc
diff --git a/extensions/common/consumer.cc b/extensions/common/consumer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..b91d891a0975b027f17b7a7bd603ecd02ea5f8d2
--- /dev/null
+++ b/extensions/common/consumer.cc
@@ -0,0 +1,35 @@
+// Copyright 2014 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 "extensions/common/consumer.h"
+
+const int ConsumerID::kDefaultInstanceID = 0;
+
+ConsumerID::ConsumerID() : host_id(std::string()) {
+}
+
+ConsumerID::ConsumerID(HostType host_type,
+                       const std::string& host_id,
+                       InstanceType instance_type,
+                       int instance_id)
+    : host_type(host_type),
+      host_id(host_id),
+      instance_type(instance_type),
+      instance_id(instance_id) {
+}
+
+bool ConsumerID::operator<(const ConsumerID& id) const {
+  return host_type < id.host_type ||
+         (host_type == id.host_type && host_id.compare(id.host_id) < 0) ||
+         (host_type == id.host_type && host_id.compare(id.host_id) == 0 &&
+          instance_type < id.instance_type) ||
+         (host_type == id.host_type && host_id.compare(id.host_id) == 0 &&
+          instance_type == id.instance_type && instance_id < id.instance_id);
+}
+
+Consumer::Consumer() {
+}
+
+Consumer::~Consumer() {
+}