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

src/d8.cc

 // Copyright 2012 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 <errno.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
 
 #include <algorithm>
@@ skipping 2521 matching lines @@
 
   return true;
 }
 
 
 int Shell::RunMain(Isolate* isolate, int argc, char* argv[], bool last_run) {
   for (int i = 1; i < options.num_isolates; ++i) {
     options.isolate_sources[i].StartExecuteInThread();
   }
   {
-    if (options.lcov_file) debug::Coverage::TogglePrecise(isolate, true);
+    if (options.lcov_file) {
+      debug::Coverage::SelectMode(isolate, debug::Coverage::kPreciseCount);
+    }
     HandleScope scope(isolate);
     Local<Context> context = CreateEvaluationContext(isolate);
     if (last_run && options.use_interactive_shell()) {
       // Keep using the same context in the interactive shell.
       evaluation_context_.Reset(isolate, context);
     }
     {
       Context::Scope cscope(context);
       InspectorClient inspector_client(context, options.enable_inspector);
       PerIsolateData::RealmScope realm_scope(PerIsolateData::Get(isolate));
@@ skipping 498 matching lines @@
 }
 
 }  // namespace v8
 
 
 #ifndef GOOGLE3
 int main(int argc, char* argv[]) {
   return v8::Shell::Main(argc, argv);
 }
 #endif