bind-gen: Enable the new bindings of IDL callbacks

Enables the new bindings of IDL callback functions and
IDL callback interfaces.

No behavioral change, but reduces the APK size by 7 KBytes.

Bug: 839389
Change-Id: I8281c922ac310a277954bf35864fc85c7bb9932b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2370682
Commit-Queue: Yuki Shiino <yukishiino@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Hitoshi Yoshida <peria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#816467}

third_party/blink/renderer/config.gni

@@ -43,11 +43,11 @@ declare_args() {
 
   # If true, the new implementation (experimental) of Blink-V8 bindings
   # (of IDL callback function) is used.
-  use_blink_v8_binding_new_idl_callback_function = false
+  use_blink_v8_binding_new_idl_callback_function = true
 
   # If true, the new implementation (experimental) of Blink-V8 bindings
   # (of IDL callback interface) is used.
-  use_blink_v8_binding_new_idl_callback_interface = false
+  use_blink_v8_binding_new_idl_callback_interface = true
 
   # If true, the new implementation (experimental) of Blink-V8 bindings
   # (of IDL dictionary) is used.