Support more configurability in GN toolchains

tools/gn/builder_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/builder.h"
 #include "tools/gn/loader.h"
 #include "tools/gn/target.h"
 #include "tools/gn/test_with_scope.h"
 #include "tools/gn/toolchain.h"
@@ skipping 53 matching lines @@
         builder_(new Builder(loader_.get())),
         settings_(&build_settings_, std::string()),
         scope_(&settings_) {
     build_settings_.SetBuildDir(SourceDir("//out/"));
     settings_.set_toolchain_label(Label(SourceDir("//tc/"), "default"));
     settings_.set_default_toolchain_label(settings_.toolchain_label());
   }
 
   Toolchain* DefineToolchain() {
     Toolchain* tc = new Toolchain(&settings_, settings_.toolchain_label());
+    TestWithScope::SetupToolchain(tc);
     builder_->ItemDefined(scoped_ptr<Item>(tc));
     return tc;
   }
 
  protected:
   scoped_refptr<MockLoader> loader_;
   scoped_refptr<Builder> builder_;
   BuildSettings build_settings_;
   Settings settings_;
   Scope scope_;
@@ skipping 93 matching lines @@
 
 // Tests that the should generate bit is set and propogated properly.
 TEST_F(BuilderTest, ShouldGenerate) {
   DefineToolchain();
 
   // Define a secondary toolchain.
   Settings settings2(&build_settings_, "secondary/");
   Label toolchain_label2(SourceDir("//tc/"), "secondary");
   settings2.set_toolchain_label(toolchain_label2);
   Toolchain* tc2 = new Toolchain(&settings2, toolchain_label2);
+  TestWithScope::SetupToolchain(tc2);
   builder_->ItemDefined(scoped_ptr<Item>(tc2));
 
   // Construct a dependency chain: A -> B. A is in the default toolchain, B
   // is not.
   Label a_label(SourceDir("//foo/"), "a",
                 settings_.toolchain_label().dir(), "a");
   Label b_label(SourceDir("//foo/"), "b",
                 toolchain_label2.dir(), toolchain_label2.name());
 
   // First define B.
@@ skipping 11 matching lines @@
   a->set_output_type(Target::EXECUTABLE);
   builder_->ItemDefined(scoped_ptr<Item>(a));
 
   // A should have the generate bit set since it's in the default toolchain.
   BuilderRecord* a_record = builder_->GetRecord(a_label);
   EXPECT_TRUE(a_record->should_generate());
 
   // It should have gotten pushed to B.
   EXPECT_TRUE(b_record->should_generate());
 }