Import ConditionVariable class.

src/platform/mutex.h

Index: src/platform/mutex.h
diff --git a/src/platform/mutex.h b/src/platform/mutex.h
index 19405424102c377130f08e071387d1c616e49ab7..96832ceb41a45c150de423c405b3a00ed59e80ca 100644
--- a/src/platform/mutex.h
+++ b/src/platform/mutex.h
@@ -40,6 +40,9 @@
 namespace v8 {
 namespace internal {
 
+// Forward declarations.
+class ConditionVariable;

[Michael Starzinger, 2013/09/02 19:12:43]

There should be no need to forward declare this if it is only used to declare a
friend.

[Benedikt Meurer, 2013/09/03 07:27:39]

Done.

+
 // ----------------------------------------------------------------------------
 // Mutex
 //
@@ -94,6 +97,22 @@ class Mutex V8_FINAL {
   int level_;
 #endif
 
+  V8_INLINE(void CheckHeldAndUnmark()) {

[Michael Starzinger, 2013/09/02 19:12:43]

nit: s/Check/Assert/, we use "check" to describe predicates that are also
validated in release builds, this will only be validated in debug builds.

[Benedikt Meurer, 2013/09/03 07:27:39]

Done.

+#ifdef DEBUG
+    ASSERT_EQ(1, level_);
+    level_--;
+#endif
+  }
+
+  V8_INLINE(void CheckUnheldAndMark()) {

[Michael Starzinger, 2013/09/02 19:12:43]

Likewise.

[Benedikt Meurer, 2013/09/03 07:27:39]

Done.

+#ifdef DEBUG
+    ASSERT_EQ(0, level_);
+    level_++;
+#endif
+  }
+
+  friend class ConditionVariable;
+
   DISALLOW_COPY_AND_ASSIGN(Mutex);
 };