- Add an OSThread structure which is the generic TLS structure for all C++

runtime/vm/log.cc

Index: runtime/vm/log.cc
diff --git a/runtime/vm/log.cc b/runtime/vm/log.cc
index e29432f0da8374ead7a1d3a8cb6766cfe60d2948..d576bebebf79247c6998e17a8bc2ce9c177832b9 100644
--- a/runtime/vm/log.cc
+++ b/runtime/vm/log.cc
@@ -32,7 +32,9 @@ Log* Log::Current() {
   Thread* thread = Thread::Current();
   Isolate* isolate = thread->isolate();
   if (isolate != NULL && Log::ShouldLogForIsolate(isolate)) {
-    return thread->log();
+    OSThread* os_thread = thread->os_thread();
+    ASSERT(os_thread != NULL);
+    return os_thread->log();
   } else {
     return Log::NoOpLog();
   }