MojoLPM: Fix bindings generator dependencies.

https://chromium-review.googlesource.com/c/chromium/src/+/2302609
revealed that the dependencies are broken for the MojoLPM bindings
generators. Suspect that this is also the root cause of the linked
bug

Bug: 1108739
Change-Id: I1cac1fbf2a2cc139f972f7e6e605bd4a70323c33
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2315340Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Commit-Queue: Mark Brand <markbrand@google.com>
Cr-Commit-Position: refs/heads/master@{#791891}

mojo/public/tools/bindings/BUILD.gn

@@ -79,6 +79,13 @@ action("precompile_templates") {
     "$mojom_generator_root/generators/js_templates/struct_definition.tmpl",
     "$mojom_generator_root/generators/js_templates/union_definition.tmpl",
     "$mojom_generator_root/generators/js_templates/validation_macros.tmpl",
+    "$mojom_generator_root/generators/mojolpm_templates/mojolpm.cc.tmpl",
+    "$mojom_generator_root/generators/mojolpm_templates/mojolpm.h.tmpl",
+    "$mojom_generator_root/generators/mojolpm_templates/mojolpm.proto.tmpl",
+    "$mojom_generator_root/generators/mojolpm_templates/mojolpm_from_proto_macros.tmpl",
+    "$mojom_generator_root/generators/mojolpm_templates/mojolpm_macros.tmpl",
+    "$mojom_generator_root/generators/mojolpm_templates/mojolpm_to_proto_macros.tmpl",
+    "$mojom_generator_root/generators/mojolpm_templates/mojolpm_traits_specialization_macros.tmpl",
     "$mojom_generator_root/generators/ts_templates/module_definition.tmpl",
     "$mojom_generator_root/generators/ts_templates/mojom.tmpl",
   ]
@@ -88,6 +95,7 @@ action("precompile_templates") {
   outputs = [
     "$target_gen_dir/cpp_templates.zip",
     "$target_gen_dir/java_templates.zip",
+    "$target_gen_dir/mojolpm_templates.zip",
     "$target_gen_dir/js_templates.zip",
     "$target_gen_dir/ts_templates.zip",
   ]

mojo/public/tools/bindings/mojom.gni

@@ -96,6 +96,7 @@ mojom_generator_sources =
     mojom_parser_sources + [
       "$mojom_generator_root/generators/mojom_cpp_generator.py",
       "$mojom_generator_root/generators/mojom_java_generator.py",
+      "$mojom_generator_root/generators/mojom_mojolpm_generator.py",
       "$mojom_generator_root/generators/mojom_js_generator.py",
       "$mojom_generator_root/generators/mojom_ts_generator.py",
       "$mojom_generator_script",