gn: Support build directories outside the source tree.

tools/gn/label_pattern_unittest.cc

 // Copyright 2014 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 "testing/gtest/include/gtest/gtest.h"
 #include "tools/gn/err.h"
 #include "tools/gn/label_pattern.h"
 #include "tools/gn/value.h"
 
 namespace {
@@ skipping 44 matching lines @@
     { "//foo(//foo/bar:*)", false, LabelPattern::MATCH, "", "", "" },
     { "//foo/*(*)", false, LabelPattern::MATCH, "", "", "" },
     { "//foo(//bar", false, LabelPattern::MATCH, "", "", "" },
   };
 
   for (size_t i = 0; i < arraysize(cases); i++) {
     const PatternCase& cur = cases[i];
     Err err;
     LabelPattern result =
         LabelPattern::GetPattern(current_dir, Value(NULL, cur.input), &err);
-
     EXPECT_EQ(cur.success, !err.has_error()) << i << " " << cur.input;
     EXPECT_EQ(cur.type, result.type()) << i << " " << cur.input;
     EXPECT_EQ(cur.dir, result.dir().value()) << i << " " << cur.input;
     EXPECT_EQ(cur.name, result.name()) << i << " " << cur.input;
     EXPECT_EQ(cur.toolchain, result.toolchain().GetUserVisibleName(false))
         << i << " " << cur.input;
   }
 }