Remove the dependency of Zone on Isolate

test/cctest/test-liveedit.cc

Index: test/cctest/test-liveedit.cc
diff --git a/test/cctest/test-liveedit.cc b/test/cctest/test-liveedit.cc
index 6a5f0b29970578491fe8947e1beea0f17963c533..8419dc5a4393351022a434db2326c7605a38514c 100644
--- a/test/cctest/test-liveedit.cc
+++ b/test/cctest/test-liveedit.cc
@@ -95,7 +95,7 @@ void CompareStringsOneWay(const char* s1, const char* s2,
                           int expected_diff_parameter = -1) {
   StringCompareInput input(s1, s2);
 
-  Zone zone(CcTest::i_isolate());
+  Zone zone;
 
   DiffChunkStruct* first_chunk;
   ListDiffOutputWriter writer(&first_chunk, &zone);