Only generate code for files that are specified, not their imports.

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")
 
 # TODO(azani): Remove when the switch to the new compiler is complete.
 declare_args() {
   use_old_mojom_compiler = false
 }
@@ skipping 179 matching lines @@
         "{{source}}",
         "--use_bundled_pylibs",
         "-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),
+        "--no-gen-imports",
       ]
 
       # TODO(azani): Remove when the switch to the new compiler is complete.
       if (use_old_mojom_compiler) {
         args += [ "--compiler-version=1" ]
       }
 
       if (defined(invoker.import_dirs)) {
         foreach(import_dir, invoker.import_dirs) {
           args += [
@@ skipping 201 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" ]
     }
   }
 }