dispatcher: fix test result parsing, build ranges for failure alerts, other fixes

go/src/infra/monitoring/messages/gatekeeper.go

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // These structs are used for parsing gatekeeper.json files.
 
 package messages
 
 // MasterConfig represents filtering configurtaion for alerts
 // generated about a buildbot master.
 type MasterConfig struct {
         Categories       []string                 `json:"categories"`
         TreeNotify       []string                 `json:"tree_notify"`
         SheriffClasses   []string                 `json:"sheriff_classes"`
         Builders         map[string]BuilderConfig `json:"builders"`
         ExcludedBuilders []string                 `json:"excluded_builders"`
         ExcludedSteps    []string                 `json:"excluded_steps"`
 }
 
 // BuilderConfig represents filtering configuration for alerts
 // generated about a buildbot builder.
 type BuilderConfig struct {
         ExcludedSteps     []string `json:"excluded_steps"`
         ForgivingSteps    []string `json:"forgiving_steps"`
         ForgivingOptional []string `json:"forgiving_optional"`
         SheriffClasses    []string `json:"sheriff_classes"`
         ClosingSteps      []string `json:"closing_steps"`
         ClosingOptional   []string `json:"closing_optional"`
 }
+
+// TreeMasterConfig is a named group of masters. e.g. chromium, or blink.
+type TreeMasterConfig struct {
+        BuildDB string   `json:"build-db"`
+        Masters []string `json:"masters"`
+}