Make more services' public interfaces flexible wrt location in repo.

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 17 matching lines @@
 #       current directory.
 #
 #   public_deps (optional)
 #       Note: this can contain only other mojom targets.
 #
 #   mojo_sdk_public_deps (optional)
 #       List of public deps specified relative to the parent directory of the
 #       Mojo public SDK. These deps will be added as ordinary public deps
 #       rebased to the current directory.
 #
+#   import_dirs (optional)
+#       List of import directories that will get added when processing sources.
+#
 #   testonly (optional)
 #
 #   visibility (optional)
 template("mojom") {
   assert(defined(invoker.sources),
          "\"sources\" must be defined for the $target_name template.")
 
   generator_root = rebase_path("mojo/public/tools/bindings", ".", mojo_root)
   generator_script = "$generator_root/mojom_bindings_generator.py"
   generator_sources = [
@@ skipping 100 matching lines @@
       "--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),
     ]
+
+    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
     }
     sources = process_file_template(invoker.sources, generator_cpp_outputs)
@@ skipping 68 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" ]
       }
 
       srcjars = process_file_template(invoker.sources, generator_java_outputs)
     }
   }
 }