Add an assert_no_deps variable to GN.

tools/gn/value_extractors.h

 // 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.
 
 #ifndef TOOLS_GN_VALUE_EXTRACTORS_H_
 #define TOOLS_GN_VALUE_EXTRACTORS_H_
 
 #include <string>
 #include <vector>
 
 #include "tools/gn/label_ptr.h"
 #include "tools/gn/lib_file.h"
 #include "tools/gn/unique_vector.h"
 
 class BuildSettings;
 class Err;
 class Label;
+class LabelPattern;
 class SourceDir;
 class SourceFile;
 class Value;
 
 // On failure, returns false and sets the error.
 bool ExtractListOfStringValues(const Value& value,
                                std::vector<std::string>* dest,
                                Err* err);
 
 // Looks for a list of source files relative to a given current dir.
@@ skipping 45 matching lines @@
                                const Label& current_toolchain,
                                UniqueVector<LabelTargetPair>* dest,
                                Err* err);
 
 bool ExtractRelativeFile(const BuildSettings* build_settings,
                          const Value& value,
                          const SourceDir& current_dir,
                          SourceFile* file,
                          Err* err);
 
+bool ExtractListOfLabelPatterns(const Value& value,
+                                const SourceDir& current_dir,
+                                std::vector<LabelPattern>* patterns,
+                                Err* err);
+
 #endif  // TOOLS_GN_VALUE_EXTRACTORS_H_