gn: Support build directories outside the source tree.

tools/gn/function_toolchain.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 <algorithm>
 #include <limits>
 
 #include "tools/gn/err.h"
 #include "tools/gn/functions.h"
 #include "tools/gn/parse_tree.h"
@@ skipping 293 matching lines @@
   block_scope.SetProperty(&kToolchainPropertyKey, toolchain.get());
   block->ExecuteBlockInScope(&block_scope, err);
   block_scope.SetProperty(&kToolchainPropertyKey, NULL);
   if (err->has_error())
     return Value();
 
   // Read deps (if any).
   const Value* deps_value = block_scope.GetValue(variables::kDeps, true);
   if (deps_value) {
     ExtractListOfLabels(
+        scope->settings()->build_settings(),
         *deps_value, block_scope.GetSourceDir(),
         ToolchainLabelForScope(&block_scope), &toolchain->deps(), err);
     if (err->has_error())
       return Value();
   }
 
   // Read concurrent_links (if any).
   const Value* concurrent_links_value =
       block_scope.GetValue("concurrent_links", true);
   if (concurrent_links_value) {
@@ skipping 587 matching lines @@
     return Value();
 
   Scope::KeyValueMap values;
   block_scope.GetCurrentScopeValues(&values);
   toolchain->args() = values;
 
   return Value();
 }
 
 }  // namespace functions