Get rid of deprecated methods accessing mutator_thread_ instead of current thread

runtime/vm/report.cc

 // Copyright (c) 2014, 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/report.h"
 
 #include "vm/code_patcher.h"
 #include "vm/exceptions.h"
 #include "vm/flags.h"
 #include "vm/longjump.h"
@@ skipping 134 matching lines @@
       return;
     }
     if (!FLAG_warning_as_error) {
       const String& msg = String::Handle(String::NewFormattedV(format, args));
       const String& snippet_msg = String::Handle(
           PrependSnippet(kind, script, token_pos, msg));
       OS::Print("%s", snippet_msg.ToCString());
       if (kind == kJSWarning) {
         TraceJSWarning(script, token_pos, msg);
         // Do not print stacktrace if we have not executed Dart code yet.
-        if (Isolate::Current()->top_exit_frame_info() != 0) {
+        if (Thread::Current()->top_exit_frame_info() != 0) {
           const Stacktrace& stacktrace =
               Stacktrace::Handle(Exceptions::CurrentStacktrace());
           intptr_t idx = 0;
           OS::Print("%s", stacktrace.ToCStringInternal(
               &idx, FLAG_stacktrace_depth_on_warning));
         }
       }
       return;
     }
   }
@@ skipping 86 matching lines @@
     trace_warning.AddProperty("type", "JSCompatibilityWarning");
     trace_warning.AddProperty("script", script);
     trace_warning.AddProperty("tokenPos", token_pos);
     trace_warning.AddProperty("message", message);
   }
   trace_buffer->Trace(micros, js.ToCString(), true);  // Already escaped.
 }
 
 }  // namespace dart