Dart: Removes all but native calls and the handle watcher from the snapshot.

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++ and JavaScript 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 316 matching lines @@
       dep_target_out_dir = get_label_info(d, "target_out_dir")
       deps += [ "${full_name}_dart" ]
       zip_inputs += [ "$dep_target_out_dir/$dep_name.dartzip" ]
     }
 
     output = generator_dart_zip_output
     outputs = [
       output,
     ]
 
-    rebase_base_dir = rebase_path("$root_build_dir/gen/", root_build_dir)
+    invoker_base_dir = ""
+    if (defined(invoker.base_dir)) {
+      invoker_base_dir =
+          rebase_path(invoker.base_dir, "$root_build_dir/../../", ".")
+    }
+
+    rebase_base_dir =
+        rebase_path("$root_build_dir/gen/$invoker_base_dir", root_build_dir)
     if (defined(invoker.sources)) {
       rebase_inputs = rebase_path(inputs, root_build_dir)
     }
     rebase_zip_inputs = rebase_path(zip_inputs, root_build_dir)
     rebase_output = rebase_path(output, root_build_dir)
     args = [
       "--base-dir=$rebase_base_dir",
       "--zip-inputs=$rebase_zip_inputs",
       "--output=$rebase_output",
     ]
@@ skipping 21 matching lines @@
         full_name = get_label_info(d, "label_no_toolchain")
         deps += [ "${full_name}_java" ]
       }
 
       if (defined(invoker.sources)) {
         srcjars = process_file_template(invoker.sources, generator_java_outputs)
       }
     }
   }
 }