Move platform abstraction to base library

src/base/platform/platform-macos.cc

Index: src/base/platform/platform-macos.cc
diff --git a/src/platform-macos.cc b/src/base/platform/platform-macos.cc
similarity index 98%
rename from src/platform-macos.cc
rename to src/base/platform/platform-macos.cc
index 7b6609b63fd610be0cc4f158dc719b7c772d0a7b..0e62881dc94989c35eec95410fe693299327cf09 100644
--- a/src/platform-macos.cc
+++ b/src/base/platform/platform-macos.cc
@@ -35,12 +35,12 @@
 
 #undef MAP_TYPE
 
-#include "src/platform.h"
-#include "src/utils.h"
+#include "src/base/macros.h"
+#include "src/base/platform/platform.h"
 
 
 namespace v8 {
-namespace internal {
+namespace base {
 
 
 // Constants used for mmap.
@@ -307,4 +307,4 @@ bool VirtualMemory::HasLazyCommits() {
   return false;
 }
 
-} }  // namespace v8::internal
+} }  // namespace v8::base