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

extensions/common/consumer_id.cc

Index: extensions/common/consumer_id.cc
diff --git a/extensions/common/consumer_id.cc b/extensions/common/consumer_id.cc
new file mode 100644
index 0000000000000000000000000000000000000000..45a4eba2023c76e699ad9668f08cc7ffb0fc2386
--- /dev/null
+++ b/extensions/common/consumer_id.cc
@@ -0,0 +1,61 @@
+// Copyright 2015 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_id.h"
+
+namespace {

[Devlin, 2015/01/21 23:25:20]

nit: newline

[Xi Han, 2015/01/22 17:19:36]

Done.

+// Default instance ID of a consumer who owns statically defined user scripts.
+const int kDefaultInstanceID = 0;
+
+int current_instance_id_ = kDefaultInstanceID;
+
+// Get next available instance ID.
+int GetNextID() {
+  return ++current_instance_id_;
+}
+
+}  // namespace
+
+ConsumerID::ConsumerID() {
+}
+
+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) {
+}
+
+ConsumerID::ConsumerID(HostType host_type,
+                       const std::string& host_id,
+                       InstanceType instance_type,
+                       bool is_declarative)
+    : host_type_(host_type), host_id_(host_id), instance_type_(instance_type) {
+  instance_id_ = is_declarative ? GetNextID() : kDefaultInstanceID;
+}
+
+bool ConsumerID::operator<(const ConsumerID& id) const {
+  if (host_type_ != id.host_type())
+    return host_type_ < id.host_type();
+  if (host_id_ != id.host_id())
+    return host_id_ < id.host_id();
+  if (instance_type_ != id.instance_type())
+    return instance_type_ < id.instance_type();
+  if (instance_id_ != id.instance_id())
+    return instance_id_ < id.instance_id();
+  return false;
+}
+
+void ConsumerID::operator=(const ConsumerID& id) {
+  host_type_ = id.host_type();
+  host_id_ = id.host_id();
+  instance_type_ = id.instance_type();
+  instance_id_ = id.instance_id();
+}
+
+ConsumerID::~ConsumerID() {
+}