[debug] refactor code coverage to use enum for mode.

test/cctest/test-debug.cc

Index: test/cctest/test-debug.cc
diff --git a/test/cctest/test-debug.cc b/test/cctest/test-debug.cc
index 07af24a6354db54d785571f78d422c6884dc4be1..7a78e53f49768457b1a8557bad79442b21e3a8ff 100644
--- a/test/cctest/test-debug.cc
+++ b/test/cctest/test-debug.cc
@@ -6613,7 +6613,7 @@ TEST(DebugCoverage) {
   LocalContext env;
   v8::Isolate* isolate = env->GetIsolate();
   v8::HandleScope scope(isolate);
-  v8::debug::Coverage::TogglePrecise(isolate, true);
+  v8::debug::Coverage::SelectMode(isolate, v8::debug::Coverage::kPreciseCount);
   v8::Local<v8::String> source = v8_str(
       "function f() {\n"
       "}\n"