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

runtime/lib/isolate.cc

 // Copyright (c) 2012, 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 "platform/assert.h"
 #include "vm/bootstrap_natives.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart.h"
 #include "vm/dart_api_impl.h"
 #include "vm/dart_entry.h"
@@ skipping 215 matching lines @@
 static char* String2UTF8(const String& str) {
   intptr_t len = Utf8::Length(str);
   char* result = new char[len + 1];
   str.ToUTF8(reinterpret_cast<uint8_t*>(result), len);
   result[len] = 0;
 
   return result;
 }
 
 
-static char* CanonicalizeUri(Isolate* isolate,
+static char* CanonicalizeUri(Thread* thread,
                              const Library& library,
                              const String& uri,
                              char** error) {
   char* result = NULL;
-  Zone* zone = isolate->current_zone();
+  Zone* zone = thread->zone();
+  Isolate* isolate = thread->isolate();
   Dart_LibraryTagHandler handler = isolate->library_tag_handler();
   if (handler != NULL) {
     Dart_EnterScope();
     Dart_Handle handle = handler(Dart_kCanonicalizeUrl,
                                  Api::NewHandle(isolate, library.raw()),
                                  Api::NewHandle(isolate, uri.raw()));
     const Object& obj = Object::Handle(Api::UnwrapHandle(handle));
     if (obj.IsString()) {
       result = String2UTF8(String::Cast(obj));
     } else if (obj.IsError()) {
@@ skipping 33 matching lines @@
   GET_NATIVE_ARGUMENT(Array, environment, arguments->NativeArgAt(9));
 
   GET_NATIVE_ARGUMENT(String, package_root, arguments->NativeArgAt(10));
   GET_NATIVE_ARGUMENT(Array, packages, arguments->NativeArgAt(11));
 
 
   // Canonicalize the uri with respect to the current isolate.
   const Library& root_lib =
       Library::Handle(isolate->object_store()->root_library());
   char* error = NULL;
-  char* canonical_uri = CanonicalizeUri(isolate, root_lib, uri, &error);
+  char* canonical_uri = CanonicalizeUri(thread, root_lib, uri, &error);
   if (canonical_uri == NULL) {
     const String& msg = String::Handle(String::New(error));
     ThrowIsolateSpawnException(msg);
   }
 
   char* utf8_package_root =
       package_root.IsNull() ? NULL : String2UTF8(package_root);
 
   char** utf8_package_map = NULL;
   if (!packages.IsNull()) {
@@ skipping 62 matching lines @@
   MessageWriter writer(&data, &allocator, false);
   writer.WriteMessage(msg);
 
   PortMap::PostMessage(new Message(port.Id(),
                                    data, writer.BytesWritten(),
                                    Message::kOOBPriority));
   return Object::null();
 }
 
 }  // namespace dart