Mojo: Add ErrorHandler to RemotePtr

mojo/mojo_public.gypi

 {
   'targets': [
     {
       'target_name': 'mojo_system',
       'type': 'shared_library',
       'defines': [
         'MOJO_SYSTEM_IMPLEMENTATION',
       ],
       'include_dirs': [
         '..',
@@ skipping 147 matching lines @@
     {
       'target_name': 'mojo_bindings',
       'type': 'static_library',
       'include_dirs': [
         '..'
       ],
       'sources': [
         'public/bindings/allocation_scope.h',
         'public/bindings/array.h',
         'public/bindings/buffer.h',
+        'public/bindings/error_handler.h',
         'public/bindings/passable.h',
         'public/bindings/remote_ptr.h',
         'public/bindings/type_converter.h',
         'public/bindings/lib/array.cc',
         'public/bindings/lib/array_internal.h',
         'public/bindings/lib/array_internal.cc',
         'public/bindings/lib/bindings_internal.h',
         'public/bindings/lib/bindings_serialization.cc',
         'public/bindings/lib/bindings_serialization.h',
         'public/bindings/lib/buffer.cc',
@@ skipping 63 matching lines @@
         'public/shell/service.h',
       ],
       'includes': [ 'public/bindings/mojom_bindings_generator.gypi' ],
       'export_dependent_settings': [
         'mojo_bindings',
         'mojo_system',
       ],
     },
   ],
 }