[Isolates] Fix Linux build in Isolates branch.

src/platform-linux.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 730 matching lines @@
   // If there are multiple threads that use VM, they must have a thread id
   // stored in TLS. To verify that the thread is really executing VM,
   // we check Top's data. Having that ThreadManager::RestoreThread first
   // restores ThreadLocalTop from TLS, and only then erases the TLS value,
   // reading Isolate::thread_id() should not be affected by races.
 
   Isolate* isolate = Isolate::UncheckedCurrent();
   if (isolate == NULL) return false;
 
   ThreadManager* thread_manager = isolate->thread_manager();
-  if (thread_manager->HasId() && !thread_manager->IsArchived() &&
+  if (!thread_manager->IsArchived() &&
       thread_manager->CurrentId() == isolate->thread_id()) {
     return true;
   }
   return false;
 }
 
 
 static void ProfilerSignalHandler(int signal, siginfo_t* info, void* context) {
 #ifndef V8_HOST_ARCH_MIPS
   USE(info);
@@ skipping 109 matching lines @@
 
   // This sampler is no longer the active sampler.
   active_sampler_ = NULL;
   active_ = false;
 }
 
 
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
 } }  // namespace v8::internal