[debugger] add precise mode for code coverage.

src/heap/heap.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 "src/heap/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/ast/context-slot-cache.h"
 #include "src/base/bits.h"
@@ skipping 2761 matching lines @@
   set_retained_maps(ArrayList::cast(empty_fixed_array()));
 
   set_weak_object_to_code_table(
       *WeakHashTable::New(isolate(), 16, USE_DEFAULT_MINIMUM_CAPACITY,
                           TENURED));
 
   set_weak_new_space_object_to_code_list(
       ArrayList::cast(*(factory->NewFixedArray(16, TENURED))));
   weak_new_space_object_to_code_list()->SetLength(0);
 
+  set_code_coverage_list(undefined_value());
+
   set_script_list(Smi::kZero);
 
   Handle<SeededNumberDictionary> slow_element_dictionary =
       SeededNumberDictionary::New(isolate(), 0, TENURED);
   slow_element_dictionary->set_requires_slow_elements();
   set_empty_slow_element_dictionary(*slow_element_dictionary);
 
   set_materialized_objects(*factory->NewFixedArray(0, TENURED));
 
   // Handling of script id generation is in Heap::NextScriptId().
@@ skipping 102 matching lines @@
     case kInstanceofCacheAnswerRootIndex:
     case kCodeStubsRootIndex:
     case kEmptyScriptRootIndex:
     case kScriptListRootIndex:
     case kMaterializedObjectsRootIndex:
     case kMicrotaskQueueRootIndex:
     case kDetachedContextsRootIndex:
     case kWeakObjectToCodeTableRootIndex:
     case kWeakNewSpaceObjectToCodeListRootIndex:
     case kRetainedMapsRootIndex:
+    case kCodeCoverageListRootIndex:
     case kNoScriptSharedFunctionInfosRootIndex:
     case kWeakStackTraceListRootIndex:
     case kSerializedTemplatesRootIndex:
     case kSerializedGlobalProxySizesRootIndex:
     case kPublicSymbolTableRootIndex:
     case kApiSymbolTableRootIndex:
     case kApiPrivateSymbolTableRootIndex:
 // Smi values
 #define SMI_ENTRY(type, name, Name) case k##Name##RootIndex:
       SMI_ROOT_LIST(SMI_ENTRY)
@@ skipping 3638 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8