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

extensions/common/consumer.cc

+// 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;
+int ConsumerID::current_instance_id_ = ConsumerID::kDefaultInstanceID;
+
+ConsumerID::ConsumerID()
+    : host_type_(ConsumerID::EXTENSIONS),
+      host_id_(std::string()),
+      instance_type_(ConsumerID::TAB),
+      instance_id_(ConsumerID::kDefaultInstanceID) {
+}
+
+ConsumerID::ConsumerID(const ConsumerID& other)

[Fady Samuel, 2015/01/09 22:07:24]

What about having a single InvalidConsumerID? See

https://code.google.com/p/chromium/codesearch#chromium/src/url/gurl.cc&q=GURL...

[Xi Han, 2015/01/09 22:59:33]

Good idea, updated.

+    : host_type_(other.host_type()),
+      host_id_(other.host_id()),
+      instance_type_(other.instance_type()),
+      instance_id_(other.instance_id()) {
+}
+
+ConsumerID::ConsumerID(HostType host_type,
+                       const std::string& host_id,
+                       InstanceType instance_type,
+                       int instance_id)

[Fady Samuel, 2015/01/09 22:07:24]

Get rid of this. 

[Xi Han, 2015/01/09 22:59:32]

As discuss offline, this constructor is still needed when pickle and unpickle
user scripts from shared memory regions. 

+    : host_type_(host_type),
+      host_id_(host_id),
+      instance_type_(instance_type),
+      instance_id_(instance_id) {

[Fady Samuel, 2015/01/09 22:07:24]

instance_id_(++current_instance_id_)

[Xi Han, 2015/01/09 22:59:32]

Same reason as above.

+}
+
+// static
+int ConsumerID::GetNextID() {
+  return ++current_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());
+}
+
+ConsumerID::~ConsumerID() {
+}
+
+Consumer::Consumer() {
+}
+
+Consumer::~Consumer() {
+}