Move atomic ops and related files to base library

src/base/once.h

Index: src/base/once.h
diff --git a/src/once.h b/src/base/once.h
similarity index 93%
rename from src/once.h
rename to src/base/once.h
index f319125c052fee7dd9a227057e213a9486b215ef..a8e8437afaad392d2bdb4247e69d18e336e59695 100644
--- a/src/once.h
+++ b/src/base/once.h
@@ -49,19 +49,19 @@
 // whatsoever to statically-initialize its synchronization primitives, so our
 // only choice is to assume that dynamic initialization is single-threaded.
 
-#ifndef V8_ONCE_H_
-#define V8_ONCE_H_
+#ifndef V8_BASE_ONCE_H_
+#define V8_BASE_ONCE_H_
 
-#include "src/atomicops.h"
+#include "src/base/atomicops.h"
 
 namespace v8 {
-namespace internal {
+namespace base {
 
 typedef AtomicWord OnceType;
 
 #define V8_ONCE_INIT 0
 
-#define V8_DECLARE_ONCE(NAME) ::v8::internal::OnceType NAME
+#define V8_DECLARE_ONCE(NAME) ::v8::base::OnceType NAME
 
 enum {
   ONCE_STATE_UNINITIALIZED = 0,
@@ -95,6 +95,6 @@ inline void CallOnce(OnceType* once,
   }
 }
 
-} }  // namespace v8::internal
+} }  // namespace v8::base
 
-#endif  // V8_ONCE_H_
+#endif  // V8_BASE_ONCE_H_