Fix cctest + unittest to work with an external snapshot.

test/cctest/cctest.cc

Index: test/cctest/cctest.cc
diff --git a/test/cctest/cctest.cc b/test/cctest/cctest.cc
index 170aa5a8a5fdc59a9e03d15f5fd264697c4774ba..08fb01bc291860c01071bafd35f11b00ae01afd5 100644
--- a/test/cctest/cctest.cc
+++ b/test/cctest/cctest.cc
@@ -34,6 +34,10 @@
 #include "test/cctest/profiler-extension.h"
 #include "test/cctest/trace-extension.h"
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+#include "src/startup-data-util.h"
+#endif  // V8_USE_EXTERNAL_STARTUP_DATA
+
 #if V8_OS_WIN
 #include <windows.h>  // NOLINT
 #if V8_CC_MSVC
@@ -166,6 +170,9 @@ int main(int argc, char* argv[]) {
   v8::V8::InitializePlatform(platform);
   v8::internal::FlagList::SetFlagsFromCommandLine(&argc, argv, true);
   v8::V8::Initialize();
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+  v8::StartupDataHandler startup_data(argv[0], NULL, NULL);
+#endif
 
   CcTestArrayBufferAllocator array_buffer_allocator;
   v8::V8::SetArrayBufferAllocator(&array_buffer_allocator);