C++ bindings: separate out serialization source set, have "mojom" targets optionally use serializat…

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 27f9cf75079f49d62d51c6376c5bfe4723ab01d7..01726c9c32f8c4caa07b0febb7a8e743044cff89 100644
--- a/mojo/public/cpp/bindings/BUILD.gn
+++ b/mojo/public/cpp/bindings/BUILD.gn
@@ -4,13 +4,12 @@
 
 import("../../mojo_sdk.gni")
 
-mojo_sdk_source_set("bindings") {
+# This target provides source files and dependencies required for serializing
+# mojom types and has no references to the rest of the mojo system. It needs to
+# be linked with an |Environment| implementation for logging.
+mojo_sdk_source_set("serialization") {
   sources = [
     "array.h",
-    "binding.h",
-    "interface_ptr.h",
-    "interface_ptr_info.h",
-    "interface_request.h",
     "lib/array_internal.cc",
     "lib/array_internal.h",
     "lib/array_serialization.h",
@@ -20,6 +19,43 @@ mojo_sdk_source_set("bindings") {
     "lib/bounds_checker.cc",
     "lib/bounds_checker.h",
     "lib/buffer.h",
+    "lib/fixed_buffer.cc",
+    "lib/fixed_buffer.h",
+    "lib/iterator_util.h",
+    "lib/map_data_internal.h",
+    "lib/map_internal.h",
+    "lib/map_serialization.h",
+    "lib/string_serialization.cc",
+    "lib/string_serialization.h",
+    "lib/template_util.h",
+    "lib/union_accessor.h",
+    "lib/validate_params.h",
+    "lib/validation_errors.cc",
+    "lib/validation_errors.h",
+    "lib/validation_util.cc",
+    "lib/validation_util.h",
+    "map.h",
+    "string.h",
+    "struct_ptr.h",
+    "type_converter.h",
+  ]
+
+  public_deps = [
+    ":callback",
+  ]
+
+  mojo_sdk_public_deps = [
+    "mojo/public/cpp/environment",
+    "mojo/public/cpp/system",
+  ]
+}
+
+mojo_sdk_source_set("bindings") {
+  sources = [
+    "binding.h",
+    "interface_ptr.h",
+    "interface_ptr_info.h",
+    "interface_request.h",
     "lib/connector.cc",
     "lib/connector.h",
     "lib/control_message_handler.cc",
@@ -28,13 +64,7 @@ mojo_sdk_source_set("bindings") {
     "lib/control_message_proxy.h",
     "lib/filter_chain.cc",
     "lib/filter_chain.h",
-    "lib/fixed_buffer.cc",
-    "lib/fixed_buffer.h",
     "lib/interface_ptr_internal.h",
-    "lib/iterator_util.h",
-    "lib/map_data_internal.h",
-    "lib/map_internal.h",
-    "lib/map_serialization.h",
     "lib/message.cc",
     "lib/message_builder.cc",
     "lib/message_builder.h",
@@ -42,36 +72,22 @@ mojo_sdk_source_set("bindings") {
     "lib/message_header_validator.cc",
     "lib/message_header_validator.h",
     "lib/message_internal.h",
+    "lib/message_validation.cc",
+    "lib/message_validation.h",
     "lib/no_interface.cc",
     "lib/router.cc",
     "lib/router.h",
-    "lib/string_serialization.cc",
-    "lib/string_serialization.h",
-    "lib/union_accessor.h",
-    "lib/validate_params.h",
-    "lib/validation_errors.cc",
-    "lib/validation_errors.h",
-    "lib/validation_util.cc",
-    "lib/validation_util.h",
-    "map.h",
     "message.h",
     "message_filter.h",
     "no_interface.h",
-    "string.h",
     "strong_binding.h",
-    "struct_ptr.h",
-    "type_converter.h",
   ]
 
-  deps = [
-    ":callback",
+  public_deps = [
+    ":serialization",
   ]
 
-  mojo_sdk_deps = [
-    "mojo/public/cpp/environment",
-    "mojo/public/cpp/system",
-    "mojo/public/interfaces/bindings:bindings_cpp_sources",
-  ]
+  mojo_sdk_deps = [ "mojo/public/interfaces/bindings:bindings_cpp_sources" ]
 }
 
 mojo_sdk_source_set("callback") {