Per isolate Log with block support

runtime/vm/thread.h

 // Copyright (c) 2015, 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.
 
 #ifndef VM_THREAD_H_
 #define VM_THREAD_H_
 
 #include "vm/isolate.h"
 
 namespace dart {
@@ skipping 13 matching lines @@
   // The topmost zone used for allocation in this thread.
   Zone* zone() {
     return reinterpret_cast<BaseIsolate*>(this)->current_zone();
   }
 
   // The isolate that this thread is operating on.
   Isolate* isolate() {
     return reinterpret_cast<Isolate*>(this);
   }
 
+  // The log for this thread.
+  Log* Log() {
+    return reinterpret_cast<Isolate*>(this)->Log();
+  }
+
  private:
   DISALLOW_COPY_AND_ASSIGN(Thread);
 };
 
 }  // namespace dart
 
 #endif  // VM_THREAD_H_