Move more Mojo bindings helpers out of internal namespace

mojo/public/cpp/bindings/BUILD.gn

Index: mojo/public/cpp/bindings/BUILD.gn
diff --git a/mojo/public/cpp/bindings/BUILD.gn b/mojo/public/cpp/bindings/BUILD.gn
index 8ff7905578ee8d4b35703eddaa320fd2dfc13bb2..d34d77040c41d96f78ea6fa2bf5eaf9ec4c6211e 100644
--- a/mojo/public/cpp/bindings/BUILD.gn
+++ b/mojo/public/cpp/bindings/BUILD.gn
@@ -17,6 +17,7 @@ source_set("bindings") {
     "associated_interface_request.h",
     "binding.h",
     "binding_set.h",
+    "connector.h",
     "enum_traits.h",
     "interface_endpoint_client.h",
     "interface_endpoint_controller.h",
@@ -35,7 +36,6 @@ source_set("bindings") {
     "lib/bindings_internal.h",
     "lib/buffer.h",
     "lib/connector.cc",
-    "lib/connector.h",
     "lib/control_message_handler.cc",
     "lib/control_message_handler.h",
     "lib/control_message_proxy.cc",
@@ -56,7 +56,6 @@ source_set("bindings") {
     "lib/message_builder.h",
     "lib/message_filter.cc",
     "lib/message_header_validator.cc",
-    "lib/message_header_validator.h",
     "lib/message_internal.h",
     "lib/multiplex_router.cc",
     "lib/multiplex_router.h",
@@ -69,10 +68,7 @@ source_set("bindings") {
     "lib/native_struct_serialization.h",
     "lib/no_interface.cc",
     "lib/pipe_control_message_handler.cc",
-    "lib/pipe_control_message_handler.h",
-    "lib/pipe_control_message_handler_delegate.h",
     "lib/pipe_control_message_proxy.cc",
-    "lib/pipe_control_message_proxy.h",
     "lib/router.cc",
     "lib/router.h",
     "lib/scoped_interface_endpoint_handle.cc",
@@ -87,7 +83,6 @@ source_set("bindings") {
     "lib/sync_call_restrictions.cc",
     "lib/sync_handle_registry.cc",
     "lib/sync_handle_watcher.cc",
-    "lib/sync_handle_watcher.h",
     "lib/template_util.h",
     "lib/union_accessor.h",
     "lib/validate_params.h",
@@ -103,9 +98,13 @@ source_set("bindings") {
     "map_traits_stl.h",
     "message.h",
     "message_filter.h",
+    "message_header_validator.h",
     "native_enum.h",
     "native_struct.h",
     "no_interface.h",
+    "pipe_control_message_handler.h",
+    "pipe_control_message_handler_delegate.h",
+    "pipe_control_message_proxy.h",
     "scoped_interface_endpoint_handle.h",
     "stl_converters.h",
     "string.h",
@@ -118,6 +117,7 @@ source_set("bindings") {
     "struct_ptr.h",
     "sync_call_restrictions.h",
     "sync_handle_registry.h",
+    "sync_handle_watcher.h",
     "type_converter.h",
   ]