Add ProcessSnapshotMinidump, the beginning of the minidump variant of the Snapshot family

snapshot/mac/process_snapshot_mac.cc

 // Copyright 2014 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 89 matching lines @@
 }
 
 void ProcessSnapshotMac::ProcessCPUTimes(timeval* user_time,
                                          timeval* system_time) const {
   INITIALIZATION_STATE_DCHECK_VALID(initialized_);
   process_reader_.CPUTimes(user_time, system_time);
 }
 
 const std::map<std::string, std::string>&
 ProcessSnapshotMac::AnnotationsSimpleMap() const {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
   return annotations_simple_map_;
 }
 
 const SystemSnapshot* ProcessSnapshotMac::System() const {
   INITIALIZATION_STATE_DCHECK_VALID(initialized_);
   return &system_;
 }
 
 std::vector<const ThreadSnapshot*> ProcessSnapshotMac::Threads() const {
   INITIALIZATION_STATE_DCHECK_VALID(initialized_);
@@ skipping 38 matching lines @@
        process_reader_modules) {
     internal::ModuleSnapshotMac* module = new internal::ModuleSnapshotMac();
     modules_.push_back(module);
     if (!module->Initialize(&process_reader_, process_reader_module)) {
       modules_.pop_back();
     }
   }
 }
 
 }  // namespace crashpad