Android Studio doesn't recognize InstanceID class

Update your Play services SDK to

compile 'com.google.android.gms:play-services:7.5.0'

Then clean your Project.

Worked for me. Hope it works for you too!

you are missing the gcm

add on your gradle:

compile "com.google.android.gms:play-services-gcm:10.2.6"

Basically, you have to use the latest version of the Google Play Services, Android Support Repository and Google Repository for this to work, and then include the latest version of the Google Play Services

compile 'com.google.android.gms:play-services:7.5.0'