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

src/debug/debug-coverage.h

Index: src/debug/debug-coverage.h
diff --git a/src/debug/debug-coverage.h b/src/debug/debug-coverage.h
index 36128bc8a96388e62ca50dfd23f88c58ef523723..02c89e63f9ddff01e72dc7f382bcca90cb9abb40 100644
--- a/src/debug/debug-coverage.h
+++ b/src/debug/debug-coverage.h
@@ -39,9 +39,8 @@ class Coverage : public std::vector<CoverageScript> {
   // The ownership is transferred to the caller.
   static Coverage* Collect(Isolate* isolate, bool reset_count);
 
-  // Enable precise code coverage. This disables optimization and makes sure
-  // invocation count is not affected by GC.
-  static void TogglePrecise(Isolate* isolate, bool enable);
+  // Select code coverage mode.
+  static void SelectMode(Isolate* isolate, debug::Coverage::Mode mode);
 
  private:
   Coverage() {}