Mojo JS bindings: flip the default value of use_new_js_bindings to true.

third_party/WebKit/public/BUILD.gn

Index: third_party/WebKit/public/BUILD.gn
diff --git a/third_party/WebKit/public/BUILD.gn b/third_party/WebKit/public/BUILD.gn
index 14e632535c17422bb5110b2c4dbd015b267e8618..dbcceb8fc0faeb2dfda297d2b364a3169c8a4c39 100644
--- a/third_party/WebKit/public/BUILD.gn
+++ b/third_party/WebKit/public/BUILD.gn
@@ -757,6 +757,9 @@ mojom("mojo_bindings") {
 
   # TODO(crbug.com/714018): Convert the implementation to use OnceCallback.
   use_once_callback = false
+
+  # TODO(crbug.com/699569): Convert to use the new JS bindings.
+  use_new_js_bindings = false
 }
 
 mojom("android_mojo_bindings") {
@@ -789,6 +792,9 @@ mojom("android_mojo_bindings") {
 
   # TODO(crbug.com/714018): Convert the implementation to use OnceCallback.
   use_once_callback = false
+
+  # TODO(crbug.com/699569): Convert to use the new JS bindings.
+  use_new_js_bindings = false
 }
 
 # The offscreen_canvas_mojo_bindings is separated from the rest of mojom files