Begin migration of InterruptableThreadState into Thread.

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/base_isolate.h"
@@ skipping 615 matching lines @@
   void set_profiler_data(IsolateProfilerData* profiler_data) {
     profiler_data_ = profiler_data;
   }
 
   IsolateProfilerData* profiler_data() const {
     return profiler_data_;
   }
 
   void PrintJSON(JSONStream* stream, bool ref = true);
 
-  void set_thread_state(InterruptableThreadState* state) {
-    ASSERT((thread_state_ == NULL) || (state == NULL));
-    thread_state_ = state;
-  }
-
   InterruptableThreadState* thread_state() const {
-    return thread_state_;
+    return (mutator_thread_ == NULL) ? NULL : mutator_thread_->thread_state();
   }
 
   CompilerStats* compiler_stats() {
     return compiler_stats_;
   }
 
   // Returns the number of sampled threads.
   intptr_t ProfileInterrupt();
 
   VMTagCounters* vm_tag_counters() {
@@ skipping 191 matching lines @@
   ObjectIdRing* object_id_ring_;
 
   // Trace buffer support.
   TraceBuffer* trace_buffer_;
 
   // TimelineEvent buffer.
   TimelineEventRecorder* timeline_event_recorder_;
 
   IsolateProfilerData* profiler_data_;
   Mutex profiler_data_mutex_;
-  InterruptableThreadState* thread_state_;
 
   VMTagCounters vm_tag_counters_;
   uword user_tag_;
   RawGrowableObjectArray* tag_table_;
   RawUserTag* current_tag_;
   RawUserTag* default_tag_;
 
   RawGrowableObjectArray* collected_closures_;
   RawGrowableObjectArray* deoptimized_code_array_;
 
@@ skipping 211 matching lines @@
   uint8_t* serialized_message_;
   intptr_t serialized_message_len_;
   Isolate::Flags isolate_flags_;
   bool paused_;
   bool errors_are_fatal_;
 };
 
 }  // namespace dart
 
 #endif  // VM_ISOLATE_H_