Change the name of TokenGetterBuilder to AuthFlow.

I believe AuthFlow more succinctly describes the purpose of the type to
users reading documentation.

src/authenticator.rs

@@ -64,7 +64,7 @@ where
 }
 
 /// An internal trait implemented by flows to be used by an authenticator.
-pub trait TokenGetterBuilder<C> {
+pub trait AuthFlow<C> {
     type TokenGetter: GetToken;
 
     fn build_token_getter(self, client: hyper::Client<C>) -> Self::TokenGetter;
@@ -74,7 +74,7 @@ pub trait TokenGetterBuilder<C> {
 /// will refresh tokens as they expire as well as optionally persist tokens to
 /// disk.
 pub struct Authenticator<
-    T: TokenGetterBuilder<C::Connector>,
+    T: AuthFlow<C::Connector>,
     S: TokenStorage,
     AD: AuthenticatorDelegate,
     C: HyperClientBuilder,
@@ -87,7 +87,7 @@ pub struct Authenticator<
 
 impl<T> Authenticator<T, MemoryStorage, DefaultAuthenticatorDelegate, DefaultHyperClient>
 where
-    T: TokenGetterBuilder<<DefaultHyperClient as HyperClientBuilder>::Connector>,
+    T: AuthFlow<<DefaultHyperClient as HyperClientBuilder>::Connector>,
 {
     /// Create a new authenticator with the provided flow. By default a new
     /// hyper::Client will be created the default authenticator delegate will be
@@ -115,7 +115,7 @@ where
 
 impl<T, S, AD, C> Authenticator<T, S, AD, C>
 where
-    T: TokenGetterBuilder<C::Connector>,
+    T: AuthFlow<C::Connector>,
     S: TokenStorage,
     AD: AuthenticatorDelegate,
     C: HyperClientBuilder,
@@ -127,7 +127,7 @@ where
     ) -> Authenticator<T, S, AD, hyper::Client<NewC>>
     where
         NewC: hyper::client::connect::Connect,
-        T: TokenGetterBuilder<NewC>,
+        T: AuthFlow<NewC>,
     {
         Authenticator {
             client: hyper_client,

src/device.rs

@@ -73,7 +73,7 @@ impl<FD> DeviceFlow<FD> {
     }
 }
 
-impl<FD, C> crate::authenticator::TokenGetterBuilder<C> for DeviceFlow<FD>
+impl<FD, C> crate::authenticator::AuthFlow<C> for DeviceFlow<FD>
 where
     FD: FlowDelegate + Send + 'static,
     C: hyper::client::connect::Connect + 'static,
@@ -407,7 +407,7 @@ mod tests {
     use tokio;
 
     use super::*;
-    use crate::authenticator::TokenGetterBuilder;
+    use crate::authenticator::AuthFlow;
     use crate::helper::parse_application_secret;
 
     #[test]

src/installed.rs

@@ -124,6 +124,40 @@ impl InstalledFlow<DefaultFlowDelegate> {
     }
 }
 
+impl<FD> InstalledFlow<FD>
+where
+    FD: FlowDelegate,
+{
+    /// Use the provided FlowDelegate.
+    pub fn delegate<NewFD: FlowDelegate>(self, delegate: NewFD) -> InstalledFlow<NewFD> {
+        InstalledFlow {
+            method: self.method,
+            flow_delegate: delegate,
+            appsecret: self.appsecret,
+        }
+    }
+}
+
+impl<FD, C> crate::authenticator::AuthFlow<C> for InstalledFlow<FD>
+where
+    FD: FlowDelegate + Send + 'static,
+    C: hyper::client::connect::Connect + 'static,
+{
+    type TokenGetter = InstalledFlowImpl<FD, C>;
+
+    fn build_token_getter(self, client: hyper::Client<C>) -> Self::TokenGetter {
+        InstalledFlowImpl {
+            method: self.method,
+            fd: self.flow_delegate,
+            appsecret: self.appsecret,
+            client,
+        }
+    }
+}
+
+impl<'c, FD: 'static + FlowDelegate + Clone + Send, C: 'c + hyper::client::connect::Connect>
+    InstalledFlowImpl<FD, C>
+{
     /// Handles the token request flow; it consists of the following steps:
     /// . Obtain a authorization code with user cooperation or internal redirect.
     /// . Obtain a token and refresh token using that code.
@@ -543,7 +577,7 @@ mod tests {
     use tokio;
 
     use super::*;
-    use crate::authenticator::TokenGetterBuilder;
+    use crate::authenticator::AuthFlow;
     use crate::authenticator_delegate::FlowDelegate;
     use crate::helper::*;
     use crate::types::StringError;

src/lib.rs

@@ -93,7 +93,7 @@ mod service_account;
 mod storage;
 mod types;
 
-pub use crate::authenticator::Authenticator;
+pub use crate::authenticator::{AuthFlow, Authenticator};
 pub use crate::authenticator_delegate::{
     AuthenticatorDelegate, DefaultAuthenticatorDelegate, DefaultFlowDelegate, FlowDelegate,
     PollInformation,