Mojo C++ bindings: remove unnecessary getters/params of AssociatedGroup.

mojo/public/cpp/bindings/interface_ptr.h

Index: mojo/public/cpp/bindings/interface_ptr.h
diff --git a/mojo/public/cpp/bindings/interface_ptr.h b/mojo/public/cpp/bindings/interface_ptr.h
index 9d9a5a5fd403697907d904ff4d5d4274c326d6d6..e88be7436fb4c86b00a368bd4073b122d01272d9 100644
--- a/mojo/public/cpp/bindings/interface_ptr.h
+++ b/mojo/public/cpp/bindings/interface_ptr.h
@@ -22,8 +22,6 @@
 
 namespace mojo {
 
-class AssociatedGroup;
-
 // A pointer to a local proxy of a remote Interface implementation. Uses a
 // message pipe to communicate with the remote implementation, and automatically
 // closes the pipe and deletes the proxy on destruction. The pointer must be
@@ -186,14 +184,6 @@ class InterfacePtr {
     return state.PassInterface();
   }
 
-  // Returns the associated group that this object belongs to. Returns null if:
-  //   - this object is not bound; or
-  //   - the interface doesn't have methods to pass associated interface
-  //     pointers or requests.
-  AssociatedGroup* associated_group() {
-    return internal_state_.associated_group();
-  }
-
   bool Equals(const InterfacePtr& other) const {
     if (this == &other)
       return true;