Migrate most uses of Isolate::current_zone to Thread::zone.

runtime/vm/dart_api_impl.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 "include/dart_api.h"
 #include "include/dart_mirrors_api.h"
 #include "include/dart_native_api.h"
 
 #include "platform/assert.h"
 #include "vm/class_finalizer.h"
@@ skipping 421 matching lines @@
   return Api::NewHandle(isolate, isolate->object_store()->sticky_error());
 }
 
 
 Dart_Isolate Api::CastIsolate(Isolate* isolate) {
   return reinterpret_cast<Dart_Isolate>(isolate);
 }
 
 
 Dart_Handle Api::NewError(const char* format, ...) {
-  Isolate* isolate = Isolate::Current();
+  Thread* thread = Thread::Current();
+  Isolate* isolate = thread->isolate();
+  Zone* zone = thread->zone();
   DARTSCOPE(isolate);
   CHECK_CALLBACK_STATE(isolate);
 
   va_list args;
   va_start(args, format);
   intptr_t len = OS::VSNPrint(NULL, 0, format, args);
   va_end(args);
 
-  char* buffer = isolate->current_zone()->Alloc<char>(len + 1);
+  char* buffer = zone->Alloc<char>(len + 1);
   va_list args2;
   va_start(args2, format);
   OS::VSNPrint(buffer, (len + 1), format, args2);
   va_end(args2);
 
-  const String& message = String::Handle(isolate, String::New(buffer));
+  const String& message = String::Handle(zone, String::New(buffer));
   return Api::NewHandle(isolate, ApiError::New(message));
 }
 
 
 void Api::SetupAcquiredError(Isolate* isolate) {
   ASSERT(isolate != NULL);
   ApiState* state = isolate->api_state();
   ASSERT(state != NULL);
   state->SetupAcquiredError();
 }
@@ skipping 5319 matching lines @@
   ASSERT(stream != NULL);
   TimelineEvent* event = stream->StartEvent();
   if (event != NULL) {
     event->AsyncEnd(label, async_id);
     event->Complete();
   }
   return Api::Success();
 }
 
 }  // namespace dart