Add a UniqueVector class to GN

tools/gn/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/target_generator.h"
 
 #include "tools/gn/action_target_generator.h"
 #include "tools/gn/binary_target_generator.h"
 #include "tools/gn/build_settings.h"
 #include "tools/gn/config.h"
@@ skipping 221 matching lines @@
   CHECK(outputs.size() == value->list_value().size());
   for (size_t i = 0; i < outputs.size(); i++) {
     if (!EnsureStringIsInOutputDir(
             GetBuildSettings()->build_dir(),
             outputs[i], value->list_value()[i], allow_templates, err_))
       return;
   }
 }
 
 void TargetGenerator::FillGenericConfigs(const char* var_name,
-                                         LabelConfigVector* dest) {
+                                         UniqueVector<LabelConfigPair>* dest) {
   const Value* value = scope_->GetValue(var_name, true);
   if (value) {
-    ExtractListOfLabels(*value, scope_->GetSourceDir(),
-                        ToolchainLabelForScope(scope_), dest, err_);
+    ExtractListOfUniqueLabels(*value, scope_->GetSourceDir(),
+                              ToolchainLabelForScope(scope_), dest, err_);
   }
 }
 
 void TargetGenerator::FillGenericDeps(const char* var_name,
                                       LabelTargetVector* dest) {
   const Value* value = scope_->GetValue(var_name, true);
   if (value) {
     ExtractListOfLabels(*value, scope_->GetSourceDir(),
                         ToolchainLabelForScope(scope_), dest, err_);
   }
 }
 
 void TargetGenerator::FillForwardDependentConfigs() {
   const Value* value = scope_->GetValue(
       variables::kForwardDependentConfigsFrom, true);
   if (value) {
-    ExtractListOfLabels(*value, scope_->GetSourceDir(),
-                        ToolchainLabelForScope(scope_),
-                        &target_->forward_dependent_configs(), err_);
+    ExtractListOfUniqueLabels(*value, scope_->GetSourceDir(),
+                              ToolchainLabelForScope(scope_),
+                              &target_->forward_dependent_configs(), err_);
   }
 }