Remove debugger id, use local frame id instead.

Source/core/inspector/PageRuntimeAgent.h

Index: Source/core/inspector/PageRuntimeAgent.h
diff --git a/Source/core/inspector/PageRuntimeAgent.h b/Source/core/inspector/PageRuntimeAgent.h
index dd223c866fc31d89a45e0c6441224f8d08abdd41..5455a3caa71fd9c016da87c65edaa759cb8d30e6 100644
--- a/Source/core/inspector/PageRuntimeAgent.h
+++ b/Source/core/inspector/PageRuntimeAgent.h
@@ -56,8 +56,6 @@ public:
     void didCreateScriptContext(LocalFrame*, ScriptState*, SecurityOrigin*, int worldId);
     void willReleaseScriptContext(LocalFrame*, ScriptState*);
 
-    int debuggerId() const { return m_debuggerId; }
-
 private:
     PageRuntimeAgent(InjectedScriptManager*, Client*, V8Debugger*, InspectorPageAgent*);
 
@@ -68,7 +66,6 @@ private:
 
     RawPtrWillBeMember<InspectorPageAgent> m_pageAgent;
     bool m_mainWorldContextCreated;
-    int m_debuggerId;
 };
 
 } // namespace blink