Enable mojo js tests which depend on mojom.js files in gen/.

mojo/common/test/test_utils_posix.cc

 // 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.
 
 #include "mojo/common/test/test_utils.h"
 
 #include <fcntl.h>
 #include <unistd.h>
 
+#include "base/base_paths.h"
+#include "base/path_service.h"
 #include "base/posix/eintr_wrapper.h"
 #include "mojo/embedder/platform_handle.h"
 
 namespace mojo {
 namespace test {
 
 bool BlockingWrite(const embedder::PlatformHandle& handle,
                    const void* buffer,
                    size_t bytes_to_write,
                    size_t* bytes_written) {
@@ skipping 46 matching lines @@
       return false;
 
     *bytes_read = 0;
   } else {
     *bytes_read = result;
   }
 
   return true;
 }
 
+base::FilePath GetFilePathForJSResource(const std::string& path) {
+  std::string binding_path = "gen/" + path + ".js";
+  base::FilePath exe_dir;
+  PathService::Get(base::DIR_EXE, &exe_dir);
+  return exe_dir.AppendASCII(binding_path);
+}
+
 }  // namespace test
 }  // namespace mojo