xds/internal/xdsclient: Add comments for exported types (#6972)

internal/internal.go

@@ -190,8 +190,9 @@ var (
 	// function makes events more predictable than relying on timer events.
 	TriggerXDSResourceNameNotFoundForTesting any // func(func(xdsresource.Type, string), string, string) error
 
-	// TriggerXDSResourceNotFoundClient invokes the testing xDS Client singleton
-	// to invoke resource not found for a resource type name and resource name.
+	// TriggerXDSResourceNameNotFoundClient invokes the testing xDS Client
+	// singleton to invoke resource not found for a resource type name and
+	// resource name.
 	TriggerXDSResourceNameNotFoundClient any // func(string, string) error
 
 	// FromOutgoingContextRaw returns the un-merged, intermediary contents of metadata.rawMD.

xds/internal/xdsclient/xdsresource/filter_chain.go

@@ -96,6 +96,8 @@ type RouteWithInterceptors struct {
 	Interceptors []resolver.ServerInterceptor
 }
 
+// UsableRouteConfiguration contains a matchable route configuration, with
+// instantiated HTTP Filters per route.
 type UsableRouteConfiguration struct {
 	VHS []VirtualHostWithInterceptors
 	Err error
@@ -504,6 +506,7 @@ func (fcm *FilterChainManager) addFilterChainsForSourcePorts(srcEntry *sourcePre
 	return nil
 }
 
+// FilterChains returns the filter chains for this filter chain manager.
 func (fcm *FilterChainManager) FilterChains() []*FilterChain {
 	return fcm.fcs
 }