workers: Rename WorkerThread to WorkerScript.

Source/platform/WebThreadSupportingGC.h

Index: Source/platform/WebThreadSupportingGC.h
diff --git a/Source/platform/WebThreadSupportingGC.h b/Source/platform/WebThreadSupportingGC.h
index f25dbc070935f19d6abe6be8bfcdadbc945e5400..d2b3761288fe0904099f40fc4c4ef49c54d98b85 100644
--- a/Source/platform/WebThreadSupportingGC.h
+++ b/Source/platform/WebThreadSupportingGC.h
@@ -68,10 +68,10 @@ private:
     OwnPtr<MessageLoopInterruptor> m_messageLoopInterruptor;
 
     // FIXME: This has to be last because of crbug.com/401397.
-    // A WorkerThread might get deleted before it had a chance to properly
+    // A WorkerScript might get deleted before it had a chance to properly
     // shut down. By deleting the WebThread first, we can guarantee that
     // no pending tasks on the thread might want to access any of the other
-    // members during the WorkerThread's destruction.
+    // members during the WorkerScript's destruction.
     OwnPtr<WebThread> m_thread;
 };