[milo] fix raw annotation stream rendering endpoint.

milo/appengine/frontend/main.go

 // Copyright 2015 The LUCI Authors. All rights reserved.
 // Use of this source code is governed under the Apache License, Version 2.0
 // that can be found in the LICENSE file.
 
 package frontend
 
 import (
         "net/http"
 
         "github.com/golang/protobuf/proto"
@@ skipping 43 matching lines @@
         r.GET("/swarming/prod/:id", basemw, swarming.BuildHandler)
 
         // Buildbucket
         r.GET("/buildbucket/:bucket/:builder", basemw, buildbucket.BuilderHandler)
 
         // Buildbot
         r.GET("/buildbot/:master/:builder/:build", basemw, buildbot.BuildHandler)
         r.GET("/buildbot/:master/:builder/", basemw, buildbot.BuilderHandler)
 
         // LogDog Milo Annotation Streams.
-        r.GET("/logdog/build/:project/*prefix", basemw, logdog.BuildHandler)
+        // This mimicks the `logdog://logdog_host/project/*path` url scheme seen on
+        // swarming tasks.
+        r.GET("/raw/build/:logdog_host/:project/*path", basemw, logdog.BuildHandler)
 
         // PubSub subscription endpoints.
         r.POST("/_ah/push-handlers/buildbot", basemw, buildbot.PubSubHandler)
 
         // pRPC style endpoints.
         api := prpc.Server{
                 UnaryServerInterceptor: grpcmon.NewUnaryServerInterceptor(nil),
         }
         milo.RegisterBuildbotServer(&api, &milo.DecoratedBuildbot{
                 Service: &buildbot.Service{},
                 Prelude: emptyPrelude,
         })
         milo.RegisterBuildInfoServer(&api, &milo.DecoratedBuildInfo{
                 Service: &buildinfo.Service{},
                 Prelude: emptyPrelude,
         })
         discovery.Enable(&api)
         api.InstallHandlers(r, gaemiddleware.BaseProd())
 
         http.DefaultServeMux.Handle("/", r)
 }