Now we have a proper C++ library, use std::unique_ptr.

Also remove the Android.libcxx.mk and other bits of stlport compatibility
mechanics.

Change-Id: Icdf7188ba3c79cdf5617672c1cfd0a68ae596a61
diff --git a/runtime/runtime.h b/runtime/runtime.h
index 07b47c3..f7074f6 100644
--- a/runtime/runtime.h
+++ b/runtime/runtime.h
@@ -82,7 +82,7 @@
 
 class Runtime {
  public:
-  typedef std::vector<std::pair<std::string, const void*> > Options;
+  typedef std::vector<std::pair<std::string, const void*>> Options;
 
   // Creates and initializes a new runtime.
   static bool Create(const Options& options, bool ignore_unrecognized)
@@ -523,7 +523,7 @@
   size_t threads_being_born_ GUARDED_BY(Locks::runtime_shutdown_lock_);
 
   // Waited upon until no threads are being born.
-  UniquePtr<ConditionVariable> shutdown_cond_ GUARDED_BY(Locks::runtime_shutdown_lock_);
+  std::unique_ptr<ConditionVariable> shutdown_cond_ GUARDED_BY(Locks::runtime_shutdown_lock_);
 
   // Set when runtime shutdown is past the point that new threads may attach.
   bool shutting_down_ GUARDED_BY(Locks::runtime_shutdown_lock_);