Getting rid of Isolate::current_zone() usage. Pass thread instead of isolate where it makes sense.

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 637 matching lines @@
                            const Instance& id);
   void RegisterServiceExtensionHandler(const String& name,
                                        const Instance& closure);
   RawInstance* LookupServiceExtensionHandler(const String& name);
 
   static void VisitIsolates(IsolateVisitor* visitor);
 
   // Handle service messages until we are told to resume execution.
   void PauseEventHandler();
 
-  // DEPRECATED: Use Thread's methods instead. During migration, these default
-  // to using the mutator thread (which must also be the current thread).
-  Zone* current_zone() const {
-    ASSERT(Thread::Current() == mutator_thread_);
-    return mutator_thread_->zone();
-  }
-  void set_current_zone(Zone* zone) {
-    ASSERT(Thread::Current() == mutator_thread_);
-    mutator_thread_->set_zone(zone);
-  }
-
   bool is_service_isolate() const { return is_service_isolate_; }
 
   static void KillAllIsolates(LibMsgId msg_id);
   static void KillIfExists(Isolate* isolate, LibMsgId msg_id);
 
   static void DisableIsolateCreation();
   static void EnableIsolateCreation();
 
  private:
   friend class Dart;  // Init, InitOnce, Shutdown.
@@ skipping 43 matching lines @@
   }
   void MakeCurrentThreadMutator(Thread* thread) {
     ASSERT(thread == Thread::Current());
     DEBUG_ASSERT(IsIsolateOf(thread));
     mutator_thread_ = thread;
   }
 #if defined(DEBUG)
   bool IsIsolateOf(Thread* thread);
 #endif  // DEBUG
 
+  // DEPRECATED: Use Thread's methods instead. During migration, these default
+  // to using the mutator thread (which must also be the current thread).
+  Zone* current_zone() const {
+    ASSERT(Thread::Current() == mutator_thread_);
+    return mutator_thread_->zone();
+  }
+
   // Accessed from generated code:
   uword stack_limit_;
   StoreBuffer* store_buffer_;
   Heap* heap_;
   uword user_tag_;
   RawUserTag* current_tag_;
   RawUserTag* default_tag_;
   ClassTable class_table_;
   bool single_step_;
 
@@ skipping 283 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_