Add a UniqueVector class to GN

tools/gn/target_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 "testing/gtest/include/gtest/gtest.h"
 #include "tools/gn/build_settings.h"
 #include "tools/gn/config.h"
 #include "tools/gn/settings.h"
 #include "tools/gn/target.h"
 #include "tools/gn/toolchain.h"
@@ skipping 203 matching lines @@
   a.deps().push_back(LabelTargetPair(&b));
   b.deps().push_back(LabelTargetPair(&c));
   c.deps().push_back(LabelTargetPair(&d));
 
   d.OnResolved();
   c.OnResolved();
   b.OnResolved();
   a.OnResolved();
 
   // C should have D in its inherited libs.
-  const std::set<const Target*>& c_inherited = c.inherited_libraries();
+  const UniqueVector<const Target*>& c_inherited = c.inherited_libraries();
   EXPECT_EQ(1u, c_inherited.size());
-  EXPECT_TRUE(c_inherited.find(&d) != c_inherited.end());
+  EXPECT_TRUE(c_inherited.IndexOf(&d) != static_cast<size_t>(-1));
 
   // B should have C and D in its inherited libs.
-  const std::set<const Target*>& b_inherited = b.inherited_libraries();
+  const UniqueVector<const Target*>& b_inherited = b.inherited_libraries();
   EXPECT_EQ(2u, b_inherited.size());
-  EXPECT_TRUE(b_inherited.find(&c) != b_inherited.end());
-  EXPECT_TRUE(b_inherited.find(&d) != b_inherited.end());
+  EXPECT_TRUE(b_inherited.IndexOf(&c) != static_cast<size_t>(-1));
+  EXPECT_TRUE(b_inherited.IndexOf(&d) != static_cast<size_t>(-1));
 
   // A should have B in its inherited libs, but not any others (the shared
   // library will include the static library and source set).
-  const std::set<const Target*>& a_inherited = a.inherited_libraries();
+  const UniqueVector<const Target*>& a_inherited = a.inherited_libraries();
   EXPECT_EQ(1u, a_inherited.size());
-  EXPECT_TRUE(a_inherited.find(&b) != a_inherited.end());
+  EXPECT_TRUE(a_inherited.IndexOf(&b) != static_cast<size_t>(-1));
 }