Try to make a NOTREACHED definition suitable for win8.

See http://build.chromium.org/p/tryserver.chromium.win/builders/win8_chromium_gn_rel/builds/5674

Testing this is a two-step process: land CL to pdfium, then try DEPS roll
in chromium against this version on the win8 trybots.

TBR=thestig@chromium.org

Review URL: https://codereview.chromium.org/1004733006

third_party/base/logging.h

diff --git a/third_party/base/logging.h b/third_party/base/logging.h
index d24f93b..98ed9c5 100644
--- a/third_party/base/logging.h
+++ b/third_party/base/logging.h
@@ -5,6 +5,7 @@
 #ifndef PDFIUM_THIRD_PARTY_BASE_LOGGING_H_
 #define PDFIUM_THIRD_PARTY_BASE_LOGGING_H_
 
+#include <assert.h>
 #include <stdlib.h>
 
 #define CHECK(condition)                                                \
@@ -13,6 +14,6 @@
     *(reinterpret_cast<volatile char*>(NULL) + 42) = 0x42;              \
   }
 
-#define NOTREACHED() abort()
+#define NOTREACHED() assert(false)
 
 #endif  // PDFIUM_THIRD_PARTY_BASE_LOGGING_H_