Fix background compilation issues when creating snapshots.

runtime/vm/isolate.h

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_ISOLATE_H_
 #define VM_ISOLATE_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/atomic.h"
@@ skipping 557 matching lines @@
   bool error_on_bad_type() const { return error_on_bad_type_; }
   bool error_on_bad_override() const { return error_on_bad_override_; }
 #endif  // defined(PRODUCT)
 
   static void KillAllIsolates(LibMsgId msg_id);
   static void KillIfExists(Isolate* isolate, LibMsgId msg_id);
 
   static void DisableIsolateCreation();
   static void EnableIsolateCreation();
 
+  void StopBackgroundCompiler();
+
  private:
   friend class Dart;  // Init, InitOnce, Shutdown.
   friend class IsolateKillerVisitor;  // Kill().
 
   explicit Isolate(const Dart_IsolateFlags& api_flags);
 
   static void InitOnce();
   static Isolate* Init(const char* name_prefix,
                        const Dart_IsolateFlags& api_flags,
                        bool is_vm_isolate = false);
@@ skipping 323 matching lines @@
   intptr_t* spawn_count_;
 
   Dart_IsolateFlags isolate_flags_;
   bool paused_;
   bool errors_are_fatal_;
 };
 
 }  // namespace dart
 
 #endif  // VM_ISOLATE_H_