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

src/debug/debug-interface.h

 // Copyright 2016 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.
 
 #ifndef V8_DEBUG_DEBUG_INTERFACE_H_
 #define V8_DEBUG_DEBUG_INTERFACE_H_
 
 #include <functional>
 
 #include "include/v8-debug.h"
@@ skipping 197 matching lines @@
   bool IsSuspended();
 
   static v8::Local<debug::GeneratorObject> Cast(v8::Local<v8::Value> value);
 };
 
 /*
  * Provide API layer between inspector and code coverage.
  */
 class V8_EXPORT_PRIVATE Coverage {
  public:
+  enum Mode {
+    // Make use of existing information in feedback vectors on the heap.
+    kBestEffort,
+    // Disable optimization and prevent feedback vectors from being garbage
+    // collected in order to get precise invocation counts.
+    kPreciseCount,
+  };
+
   class ScriptData;  // Forward declaration.
 
   class V8_EXPORT_PRIVATE FunctionData {
    public:
     int StartOffset();
     int EndOffset();
     uint32_t Count();
     MaybeLocal<String> Name();
 
    private:
@@ skipping 12 matching lines @@
 
    private:
     explicit ScriptData(i::CoverageScript* script) : script_(script) {}
     i::CoverageScript* script_;
 
     friend class v8::debug::Coverage;
   };
 
   static Coverage Collect(Isolate* isolate, bool reset_count);
 
-  static void TogglePrecise(Isolate* isolate, bool enable);
+  static void SelectMode(Isolate* isolate, Mode mode);
 
   size_t ScriptCount();
   ScriptData GetScriptData(size_t i);
   bool IsEmpty() { return coverage_ == nullptr; }
 
   ~Coverage();
 
  private:
   explicit Coverage(i::Coverage* coverage) : coverage_(coverage) {}
   i::Coverage* coverage_;
 };
 }  // namespace debug
 }  // namespace v8
 
 #endif  // V8_DEBUG_DEBUG_INTERFACE_H_