Replace hand-written IDBObserverCallback with auto-generated code

third_party/WebKit/Source/bindings/modules/v8/BUILD.gn

Index: third_party/WebKit/Source/bindings/modules/v8/BUILD.gn
diff --git a/third_party/WebKit/Source/bindings/modules/v8/BUILD.gn b/third_party/WebKit/Source/bindings/modules/v8/BUILD.gn
index 514da4da43850816bef0bf7408ec62d6c018b181..82d9b97d2e6a11b48e22f0828c5097b5ce560bf7 100644
--- a/third_party/WebKit/Source/bindings/modules/v8/BUILD.gn
+++ b/third_party/WebKit/Source/bindings/modules/v8/BUILD.gn
@@ -28,7 +28,8 @@ idl_compiler("generate_bindings_modules_v8_interfaces") {
 idl_impl("bindings_modules_impl_generated") {
   sources = modules_dictionary_idl_files
   outputs = bindings_modules_generated_union_type_files +
-            generated_modules_dictionary_files
+            generated_modules_dictionary_files +
+            generated_modules_callback_function_files
   output_dir = bindings_modules_v8_output_dir
   target_component = "modules"
 }