Address some comments and clean up

Change-Id: I538cf204f1c89d5fc81f8fc5e5800fcf1cf87359
diff --git a/runtime/thread_state.h b/runtime/thread_state.h
index c000e61..a11d213 100644
--- a/runtime/thread_state.h
+++ b/runtime/thread_state.h
@@ -43,7 +43,7 @@
   kWaitingForMethodTracingStart,    // WAITING        TS_WAIT      waiting for method tracing to start
   kWaitingForVisitObjects,          // WAITING        TS_WAIT      waiting for visiting objects
   kWaitingForGetObjectsAllocated,   // WAITING        TS_WAIT      waiting for getting the number of allocated objects
-  kWaitingWeakRootRead,             // WAITING        TS_WAIT      waiting to read a weak root
+  kWaitingWeakGcRootRead,           // WAITING        TS_WAIT      waiting on the GC to read a weak root
   kStarting,                        // NEW            TS_WAIT      native thread started, not yet ready to run managed code
   kNative,                          // RUNNABLE       TS_RUNNING   running in a JNI native method
   kSuspended,                       // RUNNABLE       TS_RUNNING   suspended by GC or debugger