[test] Test expectations in cctest should use CHECK and not DCHECK.

test/cctest/test-strings.cc

Index: test/cctest/test-strings.cc
diff --git a/test/cctest/test-strings.cc b/test/cctest/test-strings.cc
index 8e6c4fceb5d4a8cc8deb0eafe637141e89b1d525..e4a0ba2b58a76f3db25c9a39d82d3886db8a1906 100644
--- a/test/cctest/test-strings.cc
+++ b/test/cctest/test-strings.cc
@@ -79,7 +79,7 @@ class MyRandomNumberGenerator {
   }
 
   bool next(double threshold) {
-    DCHECK(threshold >= 0.0 && threshold <= 1.0);
+    CHECK(threshold >= 0.0 && threshold <= 1.0);
     if (threshold == 1.0) return true;
     if (threshold == 0.0) return false;
     uint32_t value = next() % 100000;