Add Google provider

src/provider.rs

@@ -1,6 +1,6 @@
 //! Providers.
 
-use token::{Token, Lifetime};
+use token::{Token, Lifetime, Bearer, Expiring};
 
 /// OAuth 2.0 providers.
 pub trait Provider {
@@ -20,3 +20,15 @@ pub trait Provider {
     /// See [RFC 6749, section 3.2](http://tools.ietf.org/html/rfc6749#section-3.2).
     fn token_uri() -> &'static str;
 }
+
+/// Google OAuth 2.0 provider.
+///
+/// See [Using OAuth 2.0 to Access Google
+/// APIs](https://developers.google.com/identity/protocols/OAuth2).
+pub struct Google;
+impl Provider for Google {
+    type Lifetime = Expiring;
+    type Token = Bearer<Expiring>;
+    fn auth_uri() -> &'static str { "https://accounts.google.com/o/oauth2/v2/auth" }
+    fn token_uri() -> &'static str { "https://www.googleapis.com/oauth2/v4/token" }
+}