Remove XP Condition Variable Affordances

base/synchronization/condition_variable.h

Index: base/synchronization/condition_variable.h
diff --git a/base/synchronization/condition_variable.h b/base/synchronization/condition_variable.h
index a41b2ba5a7815e692ae44bc5a704925793b28c27..c0d1ab7c98b15c295d454f774296481bc7aa7f7d 100644
--- a/base/synchronization/condition_variable.h
+++ b/base/synchronization/condition_variable.h
@@ -75,9 +75,12 @@
 #include <pthread.h>
 #endif
 
+#if defined(OS_WIN)
+#include <windows.h>
+#endif
+
 namespace base {
 
-class ConditionVarImpl;
 class TimeDelta;
 
 class BASE_EXPORT ConditionVariable {
@@ -100,14 +103,15 @@ class BASE_EXPORT ConditionVariable {
  private:
 
 #if defined(OS_WIN)
-  ConditionVarImpl* impl_;
+  CRITICAL_SECTION* const crit_sec_;

[scottmg, 2016/04/06 18:34:04]

nit; swap order to make win & posix match.

[robliao, 2016/04/06 19:22:18]

I would have done that, but it diverges from the init order :-/. 

We get the crit_sec_ via initialization list (since it's const here) and then we
make the InitializeConditionVariable call in the constructor body.

[robliao, 2016/04/06 19:24:53]

I guess we already do that with user_lock_. Hands up in the air! Done.

+  CONDITION_VARIABLE cv_;
 #elif defined(OS_POSIX)
   pthread_cond_t condition_;
   pthread_mutex_t* user_mutex_;
-#if DCHECK_IS_ON()
-  base::Lock* user_lock_;     // Needed to adjust shadow lock state on wait.
 #endif
 
+#if DCHECK_IS_ON() && (defined(OS_WIN) || defined(OS_POSIX))
+  base::Lock* const user_lock_;  // Needed to adjust shadow lock state on wait.
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(ConditionVariable);