SUB_FRAME          57 chrome/browser/net/net_error_tab_helper_unittest.cc   enum MainFrame { SUB_FRAME, MAIN_FRAME };
SUB_FRAME          34 chrome/renderer/net/net_error_helper_core.h     SUB_FRAME,
SUB_FRAME          18 webkit/common/resource_type.h     SUB_FRAME,       // frame or iframe