[Extensions Bindings] Move signature parsing tests to their own file

extensions/renderer/BUILD.gn

 # 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("//build/config/features.gni")
 import("//extensions/features/features.gni")
 
 assert(enable_extensions)
 
 source_set("renderer") {
@@ skipping 298 matching lines @@
     "api_binding_test_util.cc",
     "api_binding_test_util.h",
     "api_binding_unittest.cc",
     "api_bindings_system_unittest.cc",
     "api_bindings_system_unittest.h",
     "api_event_handler_unittest.cc",
     "api_event_listeners_unittest.cc",
     "api_invocation_errors_unittest.cc",
     "api_last_error_unittest.cc",
     "api_request_handler_unittest.cc",
+    "api_signature_unittest.cc",
     "api_test_base.cc",
     "api_test_base.h",
     "api_test_base_unittest.cc",
     "argument_spec_unittest.cc",
     "declarative_event_unittest.cc",
     "event_unittest.cc",
     "gc_callback_unittest.cc",
     "json_schema_unittest.cc",
     "messaging_utils_unittest.cc",
     "module_system_test.cc",
@@ skipping 34 matching lines @@
     "//ui/base",
   ]
 
   if (enable_wifi_display && proprietary_codecs) {
     sources += [
       "api/display_source/wifi_display/wifi_display_elementary_stream_descriptor_unittest.cc",
       "api/display_source/wifi_display/wifi_display_media_packetizer_unittest.cc",
     ]
   }
 }