src: turn inspector raw pointer into unique_ptr

Use a unique pointer to make ownership clear.

PR-URL: #16974
Reviewed-By: Timothy Gu <timothygu99@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Eugene Ostroukhov <eostroukhov@google.com>

src/env-inl.h

@@ -326,8 +326,9 @@ inline Environment::~Environment() {
   v8::HandleScope handle_scope(isolate());
 
 #if HAVE_INSPECTOR
-  // Destroy inspector agent before erasing the context.
-  delete inspector_agent_;
+  // Destroy inspector agent before erasing the context. The inspector
+  // destructor depends on the context still being accessible.
+  inspector_agent_.reset(nullptr);
 #endif
 
   context()->SetAlignedPointerInEmbedderData(kContextEmbedderDataIndex,

src/env.h

@@ -689,7 +689,7 @@ class Environment {
 
 #if HAVE_INSPECTOR
   inline inspector::Agent* inspector_agent() const {
-    return inspector_agent_;
+    return inspector_agent_.get();
   }
 #endif
 
@@ -734,7 +734,7 @@ class Environment {
   std::map<std::string, uint64_t> performance_marks_;
 
 #if HAVE_INSPECTOR
-  inspector::Agent* const inspector_agent_;
+  std::unique_ptr<inspector::Agent> inspector_agent_;
 #endif
 
   HandleWrapQueue handle_wrap_queue_;