Fix cctest + unittest to work with an external snapshot.

test/unittests/run-all-unittests.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "include/libplatform/libplatform.h"
 #include "include/v8.h"
 #include "src/base/compiler-specific.h"
 #include "testing/gmock/include/gmock/gmock.h"
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+#include "src/startup-data-util.h"
+#endif  // V8_USE_EXTERNAL_STARTUP_DATA
+
 namespace {
 
 class DefaultPlatformEnvironment FINAL : public ::testing::Environment {
  public:
   DefaultPlatformEnvironment() : platform_(NULL) {}
   ~DefaultPlatformEnvironment() {}
 
   virtual void SetUp() OVERRIDE {
     EXPECT_EQ(NULL, platform_);
     platform_ = v8::platform::CreateDefaultPlatform();
@@ skipping 14 matching lines @@
   v8::Platform* platform_;
 };
 
 }  // namespace
 
 
 int main(int argc, char** argv) {
   testing::InitGoogleMock(&argc, argv);
   testing::AddGlobalTestEnvironment(new DefaultPlatformEnvironment);
   v8::V8::SetFlagsFromCommandLine(&argc, argv, true);
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+  v8::StartupDataHandler startup_data(argv[0], NULL, NULL);
+#endif
   return RUN_ALL_TESTS();
 }