Remove some usages of AsyncExtensionFunction::results_.

extensions/browser/extension_function.cc

Index: extensions/browser/extension_function.cc
diff --git a/extensions/browser/extension_function.cc b/extensions/browser/extension_function.cc
index c9a76ac5a8361b5e4c50501406d41b37dd27669e..52f647de5a2c9c3f2e09f6e3b6a4c390b5750cea 100644
--- a/extensions/browser/extension_function.cc
+++ b/extensions/browser/extension_function.cc
@@ -153,6 +153,22 @@ class RespondLaterAction : public ExtensionFunction::ResponseActionObject {
   void Execute() override {}
 };
 
+class AlreadyRespondedAction : public ExtensionFunction::ResponseActionObject {
+ public:
+  using DidRespondCallback = base::Callback<bool(void)>;
+  AlreadyRespondedAction(const DidRespondCallback& did_respond)
+      : did_respond_(did_respond) {}
+  ~AlreadyRespondedAction() override {}
+
+  void Execute() override {
+    DCHECK(did_respond_.Run()) << "ExtensionFunction did not call Respond(),"
+                                  " but Run() returned AlreadyResponded()";
+  }
+
+ private:
+  DidRespondCallback did_respond_;
+};
+
 // Used in implementation of ScopedUserGestureForTests.
 class UserGestureForTests {
  public:
@@ -393,6 +409,11 @@ ExtensionFunction::ResponseAction ExtensionFunction::RespondLater() {
   return ResponseAction(new RespondLaterAction());
 }
 
+ExtensionFunction::ResponseAction ExtensionFunction::AlreadyResponded() {
+  return ResponseAction(new AlreadyRespondedAction(
+      base::Bind(&ExtensionFunction::did_respond, this)));

[Devlin, 2017/01/20 00:16:02]

Why not just DCHECK() here instead, and have Execute() do nothing?

[lazyboy, 2017/01/20 00:54:47]

Right, thanks.
Done.

+}
+
 // static
 ExtensionFunction::ResponseAction ExtensionFunction::ValidationFailure(
     ExtensionFunction* function) {