mac: build fix after http://crrev.com/1364803004

snapshot/mac/thread_snapshot_mac.h

 // 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 41 matching lines @@
                   const ProcessReader::Thread& process_reader_thread);
 
   // ThreadSnapshot:
 
   const CPUContext* Context() const override;
   const MemorySnapshot* Stack() const override;
   uint64_t ThreadID() const override;
   int SuspendCount() const override;
   int Priority() const override;
   uint64_t ThreadSpecificDataAddress() const override;
+  std::vector<const MemorySnapshot*> ExtraMemory() const override;
 
  private:
 #if defined(ARCH_CPU_X86_FAMILY)
   union {
     CPUContextX86 x86;
     CPUContextX86_64 x86_64;
   } context_union_;
 #endif
   CPUContext context_;
   MemorySnapshotMac stack_;
   uint64_t thread_id_;
   uint64_t thread_specific_data_address_;
   thread_t thread_;
   int suspend_count_;
   int priority_;
   InitializationStateDcheck initialized_;
 
   DISALLOW_COPY_AND_ASSIGN(ThreadSnapshotMac);
 };
 
 }  // namespace internal
 }  // namespace crashpad
 
 #endif  // CRASHPAD_SNAPSHOT_MAC_THREAD_SNAPSHOT_MAC_H_