src/abi_namespace.h - platform/external/libcxxrt - Git at Google

 /**
  * The namespace used for the ABI declarations.  This is currently defined to
  * be the same as GNU libsupc++, however this may change in the future.
  */
 #define ABI_NAMESPACE __cxxabiv1
	/**
	* The namespace used for the ABI declarations. This is currently defined to
	* be the same as GNU libsupc++, however this may change in the future.
	*/
	#define ABI_NAMESPACE __cxxabiv1