[Extensions Bindings] Allow custom hooks to return values, throw

extensions/renderer/api_binding.cc

 // Copyright 2016 The Chromium 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 "extensions/renderer/api_binding.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/logging.h"
@@ skipping 180 matching lines @@
   std::vector<v8::Local<v8::Value>> argument_list;
   if (arguments->Length() > 0) {
     // Just copying handles should never fail.
     CHECK(arguments->GetRemaining(&argument_list));
   }
 
   bool invalid_invocation = false;
   {
     v8::TryCatch try_catch(isolate);
     APIBindingHooks::RequestResult hooks_result =
-        APIBindingHooks::RequestResult::NOT_HANDLED;
-    hooks_result = binding_hooks_->HandleRequest(api_name_, name, context,
-                                                 signature, &argument_list,
-                                                 *type_refs_);
+        binding_hooks_->HandleRequest(api_name_, name, context,
+                                      signature, &argument_list, *type_refs_);
 
-    switch (hooks_result) {
+    switch (hooks_result.code) {
       case APIBindingHooks::RequestResult::INVALID_INVOCATION:
         invalid_invocation = true;
         // Throw a type error below so that it's not caught by our try-catch.
         break;
       case APIBindingHooks::RequestResult::THROWN:
         DCHECK(try_catch.HasCaught());
         try_catch.ReThrow();
         return;
       case APIBindingHooks::RequestResult::HANDLED:
+        if (!hooks_result.return_value.IsEmpty())
+          arguments->Return(hooks_result.return_value);
         return;  // Our work here is done.
       case APIBindingHooks::RequestResult::NOT_HANDLED:
         break;  // Handle in the default manner.
     }
   }
 
   if (invalid_invocation) {
     arguments->ThrowTypeError("Invalid invocation");
     return;
   }
@@ skipping 15 matching lines @@
     arguments->ThrowTypeError("Invalid invocation");
     return;
   }
 
   DCHECK(converted_arguments);
   method_callback_.Run(name, std::move(converted_arguments), isolate, context,
                        callback);
 }
 
 }  // namespace extensions