Move platform abstraction to base library

src/base/platform/condition-variable.cc

Index: src/base/platform/condition-variable.cc
diff --git a/src/platform/condition-variable.cc b/src/base/platform/condition-variable.cc
similarity index 98%
rename from src/platform/condition-variable.cc
rename to src/base/platform/condition-variable.cc
index e180acdcb7fe91bf8eb5222734b09e5590110f8a..b4e18b74a35f4731fd81c613a72c45980faeff16 100644
--- a/src/platform/condition-variable.cc
+++ b/src/base/platform/condition-variable.cc
@@ -2,15 +2,15 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "src/platform/condition-variable.h"
+#include "src/base/platform/condition-variable.h"
 
 #include <errno.h>
 #include <time.h>
 
-#include "src/platform/time.h"
+#include "src/base/platform/time.h"
 
 namespace v8 {
-namespace internal {
+namespace base {
 
 #if V8_OS_POSIX
 
@@ -319,4 +319,4 @@ bool ConditionVariable::WaitFor(Mutex* mutex, const TimeDelta& rel_time) {
 
 #endif  // V8_OS_POSIX
 
-} }  // namespace v8::internal
+} }  // namespace v8::base