Add GN function get_label_info

tools/gn/filesystem_utils_unittest.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 "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "build/build_config.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "tools/gn/filesystem_utils.h"
 
@@ skipping 318 matching lines @@
 TEST(FilesystemUtils, GetToolchainDirs) {
   BuildSettings build_settings;
   build_settings.SetBuildDir(SourceDir("//out/Debug/"));
 
   Settings default_settings(&build_settings, "");
   EXPECT_EQ("//out/Debug/",
             GetToolchainOutputDir(&default_settings).value());
   EXPECT_EQ("//out/Debug/gen/",
             GetToolchainGenDir(&default_settings).value());
 
-  Settings other_settings(&build_settings, "two");
+  Settings other_settings(&build_settings, "two/");
   EXPECT_EQ("//out/Debug/two/",
             GetToolchainOutputDir(&other_settings).value());
   EXPECT_EQ("//out/Debug/two/gen/",
             GetToolchainGenDir(&other_settings).value());
 }
 
 TEST(FilesystemUtils, GetOutDirForSourceDir) {
   BuildSettings build_settings;
   build_settings.SetBuildDir(SourceDir("//out/Debug/"));
 
   // Test the default toolchain.
   Settings default_settings(&build_settings, "");
   EXPECT_EQ("//out/Debug/obj/",
             GetOutputDirForSourceDir(&default_settings,
                                      SourceDir("//")).value());
   EXPECT_EQ("//out/Debug/obj/foo/bar/",
             GetOutputDirForSourceDir(&default_settings,
                                      SourceDir("//foo/bar/")).value());
 
   // Secondary toolchain.
-  Settings other_settings(&build_settings, "two");
+  Settings other_settings(&build_settings, "two/");
   EXPECT_EQ("//out/Debug/two/obj/",
             GetOutputDirForSourceDir(&other_settings, SourceDir("//")).value());
   EXPECT_EQ("//out/Debug/two/obj/foo/bar/",
             GetOutputDirForSourceDir(&other_settings,
                                      SourceDir("//foo/bar/")).value());
 }
 
 TEST(FilesystemUtils, GetGenDirForSourceDir) {
   BuildSettings build_settings;
   build_settings.SetBuildDir(SourceDir("//out/Debug/"));
 
   // Test the default toolchain.
   Settings default_settings(&build_settings, "");
   EXPECT_EQ("//out/Debug/gen/",
             GetGenDirForSourceDir(&default_settings, SourceDir("//")).value());
   EXPECT_EQ("//out/Debug/gen/foo/bar/",
             GetGenDirForSourceDir(&default_settings,
                                   SourceDir("//foo/bar/")).value());
 
   // Secondary toolchain.
-  Settings other_settings(&build_settings, "two");
+  Settings other_settings(&build_settings, "two/");
   EXPECT_EQ("//out/Debug/two/gen/",
             GetGenDirForSourceDir(&other_settings, SourceDir("//")).value());
   EXPECT_EQ("//out/Debug/two/gen/foo/bar/",
             GetGenDirForSourceDir(&other_settings,
                                   SourceDir("//foo/bar/")).value());
 }
 
 // Tests handling of output dirs when build dir is the same as the root.
 TEST(FilesystemUtils, GetDirForEmptyBuildDir) {
   BuildSettings build_settings;
   build_settings.SetBuildDir(SourceDir("//"));
   Settings settings(&build_settings, "");
 
   EXPECT_EQ("//", GetToolchainOutputDir(&settings).value());
   EXPECT_EQ("//gen/", GetToolchainGenDir(&settings).value());
   EXPECT_EQ("//obj/",
             GetOutputDirForSourceDir(&settings, SourceDir("//")).value());
   EXPECT_EQ("//gen/",
             GetGenDirForSourceDir(&settings, SourceDir("//")).value());
 }