[debugger] add precise mode for code coverage.

src/isolate.h

Index: src/isolate.h
diff --git a/src/isolate.h b/src/isolate.h
index 6d35c51830795c204d86d6b0d358666869a1a711..2acfd6287c261c58e083cb0caa00dc91a233a312 100644
--- a/src/isolate.h
+++ b/src/isolate.h
@@ -960,12 +960,15 @@ class Isolate {
   bool IsDead() { return has_fatal_error_; }
   void SignalFatalError() { has_fatal_error_ = true; }
 
-  bool use_crankshaft() const;
+  bool use_crankshaft();
 
   bool initialized_from_snapshot() { return initialized_from_snapshot_; }
 
   bool NeedsSourcePositionsForProfiling() const;
 
+  bool IsCodeCoverageEnabled();
+  void SetCodeCoverageList(Object* value);
+
   double time_millis_since_init() {
     return heap_.MonotonicallyIncreasingTimeInMs() - time_millis_at_init_;
   }