Remove GN GYP generator.

tools/gn/action_target_generator.cc

 // Copyright (c) 2013 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 "tools/gn/action_target_generator.h"
 
 #include "tools/gn/build_settings.h"
 #include "tools/gn/err.h"
 #include "tools/gn/filesystem_utils.h"
 #include "tools/gn/parse_tree.h"
@@ skipping 26 matching lines @@
     : TargetGenerator(target, scope, function_call, err),
       output_type_(type) {
 }
 
 ActionTargetGenerator::~ActionTargetGenerator() {
 }
 
 void ActionTargetGenerator::DoRun() {
   target_->set_output_type(output_type_);
 
-  FillExternal();
-  if (err_->has_error())
-    return;
-
   FillSources();
   if (err_->has_error())
     return;
   if (output_type_ == Target::ACTION_FOREACH && target_->sources().empty()) {
     // Foreach rules must always have some sources to have an effect.
     *err_ = Err(function_call_, "action_foreach target has no sources.",
         "If you don't specify any sources, there is nothing to run your\n"
         "script over.");
     return;
   }
@@ skipping 84 matching lines @@
     if (!FileListHasPattern(outputs)) {
       *err_ = Err(function_call_,
           "action_foreach should have a pattern in the output.",
           "An action_foreach target should have a source expansion pattern in\n"
           "it to map source file to unique output file name. Otherwise, the\n"
           "build system can't determine when your script needs to be run.");
       return;
     }
   }
 }