Host extensions

This CL introduces HostExtension, an interface for classes that
extend the host with non-core functionality.

Extensions are added to the ChromotingHost. They are used to compile
the list of capabilities reported to the client, which can be used by
the client to determine the availability of the extension.

When a client connects, a HostExtension has the opportunity to create
an HostExtensionSession to hold client/extension state, and to handle
extension messages from that client.

BUG=

Review URL: https://codereview.chromium.org/301453003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@273652 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 24 insertions, 0 deletions

diff --git a/remoting/host/chromoting_host.cc b/remoting/host/chromoting_host.cc
index ef2ea19..942e643 100644
--- a/remoting/host/chromoting_host.cc
+++ b/remoting/host/chromoting_host.cc
@@ -141,6 +141,10 @@ void ChromotingHost::RemoveStatusObserver(HostStatusObserver* observer) {
   status_observers_.RemoveObserver(observer);
 }
 
+void ChromotingHost::AddExtension(scoped_ptr<HostExtension> extension) {
+  extensions_.push_back(extension.release());
+}
+
 void ChromotingHost::RejectAuthenticatingClient() {
   DCHECK(authenticating_client_);
   reject_authenticating_client_ = true;
@@ -230,6 +234,19 @@ void ChromotingHost::OnSessionChannelsConnected(ClientSession* client) {
                     OnClientConnected(client->client_jid()));
 }
 
+void ChromotingHost::OnSessionClientCapabilities(ClientSession* client) {
+  DCHECK(CalledOnValidThread());
+
+  // Create extension sessions from each registered extension for this client.
+  for (HostExtensionList::iterator extension = extensions_.begin();
+       extension != extensions_.end(); ++extension) {
+    scoped_ptr<HostExtensionSession> extension_session =
+        (*extension)->CreateExtensionSession(client);
+    if (extension_session)
+      client->AddExtensionSession(extension_session.Pass());
+  }
+}
+
 void ChromotingHost::OnSessionAuthenticationFailed(ClientSession* client) {
   DCHECK(CalledOnValidThread());
 
@@ -320,6 +337,13 @@ void ChromotingHost::OnIncomingSession(
       desktop_environment_factory_,
       max_session_duration_,
       pairing_registry_);
+
+  // Registers capabilities provided by host extensions.
+  for (HostExtensionList::iterator extension = extensions_.begin();
+       extension != extensions_.end(); ++extension) {
+    client->AddHostCapabilities((*extension)->GetCapabilities());
+  }
+
   clients_.push_back(client);
 }