Fix some memory leaks in the serialization tests.

test/cctest/test-serialize.cc

Index: test/cctest/test-serialize.cc
===================================================================
--- test/cctest/test-serialize.cc	(revision 5724)
+++ test/cctest/test-serialize.cc	(working copy)
@@ -216,6 +216,7 @@
   Vector<char> name = Vector<char>::New(file_name_length + 1);
   OS::SNPrintF(name, "%s.size", file_name_);
   FILE* fp = OS::FOpen(name.start(), "w");
+  name.Dispose();
   fprintf(fp, "new %d\n", new_space_used);
   fprintf(fp, "pointer %d\n", pointer_space_used);
   fprintf(fp, "data %d\n", data_space_used);
@@ -381,6 +382,7 @@
   env.Dispose();
 
   FileByteSink startup_sink(startup_name.start());
+  startup_name.Dispose();
   StartupSerializer startup_serializer(&startup_sink);
   startup_serializer.SerializeStrongReferences();
 
@@ -403,6 +405,7 @@
   Vector<char> name = Vector<char>::New(file_name_length + 1);
   OS::SNPrintF(name, "%s.size", file_name);
   FILE* fp = OS::FOpen(name.start(), "r");
+  name.Dispose();
   int new_size, pointer_size, data_size, code_size, map_size, cell_size;
   int large_size;
 #ifdef _MSC_VER
@@ -438,6 +441,7 @@
     OS::SNPrintF(startup_name, "%s.startup", FLAG_testing_serialization_file);
 
     CHECK(Snapshot::Initialize(startup_name.start()));
+    startup_name.Dispose();
 
     const char* file_name = FLAG_testing_serialization_file;
     ReserveSpaceForPartialSnapshot(file_name);
@@ -495,6 +499,7 @@
   env.Dispose();
 
   FileByteSink startup_sink(startup_name.start());
+  startup_name.Dispose();
   StartupSerializer startup_serializer(&startup_sink);
   startup_serializer.SerializeStrongReferences();
 
@@ -519,6 +524,7 @@
     OS::SNPrintF(startup_name, "%s.startup", FLAG_testing_serialization_file);
 
     CHECK(Snapshot::Initialize(startup_name.start()));
+    startup_name.Dispose();
 
     const char* file_name = FLAG_testing_serialization_file;
     ReserveSpaceForPartialSnapshot(file_name);