Get rid of deprecated methods accessing mutator_thread_ instead of current thread

runtime/vm/parser.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 "vm/parser.h"
 
 #include "lib/invocation_mirror.h"
 #include "platform/utils.h"
 #include "vm/ast_transformer.h"
 #include "vm/bootstrap.h"
@@ skipping 5792 matching lines @@
       if (tag == Dart_kCanonicalizeUrl) {
         return url.raw();
       }
       return Object::null();
     }
     ReportError(token_pos, "no library handler registered");
   }
   // Block class finalization attempts when calling into the library
   // tag handler.
   I->BlockClassFinalization();
-  Api::Scope api_scope(I);
+  Api::Scope api_scope(T);
   Dart_Handle result = handler(tag,
                                Api::NewHandle(I, library_.raw()),
                                Api::NewHandle(I, url.raw()));
   I->UnblockClassFinalization();
   if (Dart_IsError(result)) {
     // In case of an error we append an explanatory error message to the
     // error obtained from the library tag handler.
     Error& prev_error = Error::Handle(Z);
     prev_error ^= Api::UnwrapHandle(result);
     Report::LongJumpF(prev_error, script_, token_pos, "library handler failed");
@@ skipping 8478 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart