[debug,api] Do not use embedder field for debug context id.

src/debug/debug.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/debug/debug.h"
 
 #include <memory>
 
 #include "src/api.h"
 #include "src/arguments.h"
@@ skipping 2048 matching lines @@
         !IsFrameBlackboxed(it.frame());
   }
   debug_delegate_->PromiseEventOccurred(
       Utils::ToLocal(debug_scope.GetContext()), type, id, parent_id,
       created_by_user);
 }
 
 void Debug::ProcessCompileEvent(v8::DebugEvent event, Handle<Script> script) {
   // Attach the correct debug id to the script. The debug id is used by the
   // inspector to filter scripts by native context.
-  FixedArray* array = isolate_->native_context()->embedder_data();
-  script->set_context_data(array->get(v8::Context::kDebugIdIndex));
+  script->set_context_data(isolate_->native_context()->debug_context_id());
   if (ignore_events()) return;
   if (!script->IsUserJavaScript() && script->type() != i::Script::TYPE_WASM) {
     return;
   }
   if (!debug_delegate_) return;
   SuppressDebug while_processing(this);
   DebugScope debug_scope(this);
   if (debug_scope.failed()) return;
   HandleScope scope(isolate_);
   PostponeInterruptsScope postpone(isolate_);
@@ skipping 414 matching lines @@
     isolate_->Throw(*isolate_->factory()->NewEvalError(
         MessageTemplate::kNoSideEffectDebugEvaluate));
   }
   isolate_->set_needs_side_effect_check(old_needs_side_effect_check_);
   isolate_->debug()->UpdateHookOnFunctionCall();
   isolate_->debug()->side_effect_check_failed_ = false;
 }
 
 }  // namespace internal
 }  // namespace v8