Add public deps to GN

tools/gn/copy_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/copy_target_generator.h"
 
 #include "tools/gn/build_settings.h"
 #include "tools/gn/filesystem_utils.h"
 #include "tools/gn/parse_tree.h"
 #include "tools/gn/scope.h"
 #include "tools/gn/value.h"
 
 CopyTargetGenerator::CopyTargetGenerator(Target* target,
                                          Scope* scope,
                                          const FunctionCallNode* function_call,
                                          Err* err)
     : TargetGenerator(target, scope, function_call, err) {
 }
 
 CopyTargetGenerator::~CopyTargetGenerator() {
 }
 
 void CopyTargetGenerator::DoRun() {
   target_->set_output_type(Target::COPY_FILES);
 
-  FillSources();
-  if (err_->has_error())
+  if (!FillSources())
     return;
-  FillOutputs(true);
-  if (err_->has_error())
+  if (!FillOutputs(true))
     return;
 
   if (target_->sources().empty()) {
     *err_ = Err(function_call_, "Empty sources for copy command.",
         "You have to specify at least one file to copy in the \"sources\".");
     return;
   }
   if (target_->action_values().outputs().list().size() != 1) {
     *err_ = Err(function_call_, "Copy command must have exactly one output.",
         "You must specify exactly one value in the \"outputs\" array for the "
         "destination of the copy\n(see \"gn help copy\"). If there are "
         "multiple sources to copy, use source expansion\n(see \"gn help "
         "source_expansion\").");
     return;
   }
 }