Remove some dead fields from Isolate.

runtime/vm/isolate.cc

 // 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.
 
 #include "vm/isolate.h"
 
 #include "include/dart_api.h"
 #include "include/dart_native_api.h"
 #include "platform/assert.h"
 #include "platform/text_buffer.h"
@@ skipping 773 matching lines @@
       message_notify_callback_(NULL),
       name_(NULL),
       debugger_name_(NULL),
       start_time_(OS::GetCurrentTimeMicros()),
       main_port_(0),
       origin_id_(0),
       pause_capability_(0),
       terminate_capability_(0),
       errors_fatal_(true),
       object_store_(NULL),
-      top_exit_frame_info_(0),
       init_callback_data_(NULL),
       environment_callback_(NULL),
       library_tag_handler_(NULL),
       api_state_(NULL),
       debugger_(NULL),
       resume_request_(false),
       last_resume_timestamp_(OS::GetCurrentTimeMillis()),
       has_compiled_code_(false),
       random_(),
       simulator_(NULL),
       mutex_(new Mutex()),
       symbols_mutex_(new Mutex()),
       type_canonicalization_mutex_(new Mutex()),
       constant_canonicalization_mutex_(new Mutex()),
       megamorphic_lookup_mutex_(new Mutex()),
       message_handler_(NULL),
       spawn_state_(NULL),
       is_runnable_(false),
       gc_prologue_callback_(NULL),
       gc_epilogue_callback_(NULL),
       defer_finalization_count_(0),
       pending_deopts_(new MallocGrowableArray<PendingLazyDeopt>),
       deopt_context_(NULL),
       is_service_isolate_(false),
-      stacktrace_(NULL),
-      stack_frame_index_(-1),
       last_allocationprofile_accumulator_reset_timestamp_(0),
       last_allocationprofile_gc_timestamp_(0),
       object_id_ring_(NULL),
       tag_table_(GrowableObjectArray::null()),
       deoptimized_code_array_(GrowableObjectArray::null()),
       sticky_error_(Error::null()),
       background_compiler_(NULL),
       background_compiler_disabled_depth_(0),
       pending_service_extension_calls_(GrowableObjectArray::null()),
       registered_service_extension_handlers_(GrowableObjectArray::null()),
@@ skipping 2136 matching lines @@
 void IsolateSpawnState::DecrementSpawnCount() {
   ASSERT(spawn_count_monitor_ != NULL);
   ASSERT(spawn_count_ != NULL);
   MonitorLocker ml(spawn_count_monitor_);
   ASSERT(*spawn_count_ > 0);
   *spawn_count_ = *spawn_count_ - 1;
   ml.Notify();
 }
 
 }  // namespace dart