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

mojo/public/tools/bindings/mojom.gni

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("../../mojo_sdk.gni")
 
 # Generate C++/JavaScript/Java/Python/Dart/Go source files from mojom files. The
 # output files will go under the generated file directory tree with the same
 # path as each input file.
 #
@@ skipping 173 matching lines @@
         "-d",
         rebase_path("//", root_build_dir),
         "-I",
         rebase_path("//", root_build_dir),
         "-I",
         rebase_path(mojo_root, root_build_dir),
         "-o",
         rebase_path(root_gen_dir),
       ]
 
+      if (defined(invoker.dataonly) && invoker.dataonly) {
+        args += [ "--cpp_dataonly" ]
+      }
+
       if (defined(invoker.import_dirs)) {
         foreach(import_dir, invoker.import_dirs) {
           args += [
             "-I",
             rebase_path(import_dir, root_build_dir),
           ]
         }
       }
     }
   }
 
   source_set(target_name) {
     if (defined(invoker.visibility)) {
       visibility = invoker.visibility
     }
     if (defined(invoker.testonly)) {
       testonly = invoker.testonly
     }
     if (defined(invoker.sources)) {
       data = process_file_template(invoker.sources, generator_js_outputs)
     }
 
     public_configs =
         rebase_path([ "mojo/public/build/config:mojo_sdk" ], ".", mojo_root)
 
-    public_deps = rebase_path([ "mojo/public/cpp/bindings" ], ".", mojo_root)
+    if (defined(invoker.dataonly) && invoker.dataonly) {
+      public_deps = rebase_path([ "mojo/public/cpp/bindings:serialization" ],
+                                ".",
+                                mojo_root)
+    } else {
+      public_deps = rebase_path([ "mojo/public/cpp/bindings" ], ".", mojo_root)
+    }
+
     if (defined(invoker.sources)) {
       public_deps += [ ":${cpp_sources_target_name}" ]
     }
     public_deps += rebased_mojo_sdk_public_deps
     if (defined(invoker.public_deps)) {
       public_deps += invoker.public_deps
     }
 
     deps = []
     if (defined(invoker.sources)) {
@@ skipping 143 matching lines @@
         # //mojo/something:something and we can append "_java" to get the java
         # dependency name.
         full_name = get_label_info(d, "label_no_toolchain")
         deps += [ "${full_name}_java" ]
       }
 
       srcjar_deps = [ ":$java_srcjar_target_name" ]
     }
   }
 }