Reduce header dependencies in base/

base/condition_variable.h

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // ConditionVariable wraps pthreads condition variable synchronization or, on
 // Windows, simulates it.  This functionality is very helpful for having
 // several threads wait for an event, as is common with a thread pool managed
 // by a master.  The meaning of such an event in the (worker) thread pool
 // scenario is that additional tasks are now available for processing.  It is
 // used in Chrome in the DNS prefetching system to notify worker threads that
@@ skipping 47 matching lines @@
 // thread that has Wait()ed the longest is selected. The default policy
 // may improve performance, as the selected thread may have a greater chance of
 // having some of its stack data in various CPU caches.
 //
 // For a discussion of the many very subtle implementation details, see the FAQ
 // at the end of condition_variable_win.cc.
 
 #ifndef BASE_CONDITION_VARIABLE_H_
 #define BASE_CONDITION_VARIABLE_H_
 
+#include "build/build_config.h"
+
+#if defined(OS_WIN)
+#include <windows.h>
+#elif defined(OS_POSIX)
+#include <pthread.h>
+#endif
+
+#include "base/basictypes.h"
 #include "base/lock.h"
 
 namespace base {
   class TimeDelta;
 }
 
 class ConditionVariable {
  public:
   // Construct a cv for use with ONLY one user lock.
   explicit ConditionVariable(Lock* user_lock);
@@ skipping 87 matching lines @@
 
   pthread_cond_t condition_;
   pthread_mutex_t* user_mutex_;
 
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(ConditionVariable);
 };
 
 #endif  // BASE_CONDITION_VARIABLE_H_