I just saw that google deprecated the C2DM and replace it by GCM. On their website they describe us, step by step, the way to follow to install the GCM library required to start implementing the new android push notification (or Cloud Messaging, as they name it).
On the "Install the Helper Libraries" is written:
To perform the steps described in the following sections, you must first install the helper libraries (reference: client and server). From the SDK Manager, install Extras > Google Cloud Messaging for Android Library. This creates a gcm directory under YOUR_SDK_ROOT/extras/google/ containing these subdirectories: gcm-client, gcm-demo-appengine, gcm-demo-client, gcm-demo-server, and gcm-server.
I opened the SDK manager from Eclipse, but under the Extras is nothing except "Intel hardware accelerated execution manager". I don't see something else.
How do I find/add/install the GCM in SDK manager?