Add support for user defined "pool" to GN.

tools/gn/ninja_build_writer_unittest.cc

 // Copyright 2016 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 <sstream>
 
 #include "testing/gtest/include/gtest/gtest.h"
 #include "tools/gn/ninja_build_writer.h"
+#include "tools/gn/pool.h"
 #include "tools/gn/scheduler.h"
 #include "tools/gn/target.h"
 #include "tools/gn/test_with_scope.h"
 
 TEST(NinjaBuildWriter, TwoTargets) {
   Scheduler scheduler;
   TestWithScope setup;
   Err err;
 
   Target target_foo(setup.settings(), Label(SourceDir("//foo/"), "bar"));
   target_foo.set_output_type(Target::ACTION);
   target_foo.action_values().set_script(SourceFile("//foo/script.py"));
   target_foo.action_values().outputs() = SubstitutionList::MakeForTest(
       "//out/Debug/out1.out", "//out/Debug/out2.out");
   target_foo.SetToolchain(setup.toolchain());
   ASSERT_TRUE(target_foo.OnResolved(&err));
 
   Target target_bar(setup.settings(), Label(SourceDir("//bar/"), "bar"));
   target_bar.set_output_type(Target::ACTION);
   target_bar.action_values().set_script(SourceFile("//bar/script.py"));
   target_bar.action_values().outputs() = SubstitutionList::MakeForTest(
       "//out/Debug/out3.out", "//out/Debug/out4.out");
   target_bar.SetToolchain(setup.toolchain());
   ASSERT_TRUE(target_bar.OnResolved(&err));
 
+  Pool swiming_pool(setup.settings(),
+                    Label(SourceDir("//swiming/"), "pool",
+                          SourceDir("//other/"), "toolchain"));
+  swiming_pool.set_depth(42);
+
   std::ostringstream ninja_out;
   std::ostringstream depfile_out;
   std::vector<const Settings*> all_settings = {setup.settings()};
   std::vector<const Target*> targets = {&target_foo, &target_bar};
+  std::vector<const Pool*> all_pools = {&swiming_pool};
   NinjaBuildWriter writer(setup.build_settings(), all_settings,
-                          setup.toolchain(), targets, ninja_out, depfile_out);
+                          setup.toolchain(), targets, all_pools, ninja_out,
+                          depfile_out);
   ASSERT_TRUE(writer.Run(&err));
 
   const char expected_rule_gn[] = "rule gn\n";
   const char expected_build_ninja[] =
       "build build.ninja: gn\n"
       "  generator = 1\n"
       "  depfile = build.ninja.d\n"
       "\n";
   const char expected_link_pool[] =
       "pool link_pool\n"
       "  depth = 0\n"
+      "\n"
+      "pool other_toolchain_swiming_pool\n"
+      "  depth = 42\n"
       "\n";
   const char expected_toolchain[] =
       "subninja toolchain.ninja\n"
       "\n";
   const char expected_targets[] =
       "build bar: phony obj/bar/bar.stamp\n"
       "build foo$:bar: phony obj/foo/bar.stamp\n"
       "build bar$:bar: phony obj/bar/bar.stamp\n"
       "\n";
   const char expected_root_target[] =
@@ skipping 34 matching lines @@
   target_bar.action_values().set_script(SourceFile("//bar/script.py"));
   target_bar.action_values().outputs() = SubstitutionList::MakeForTest(
       "//out/Debug/out3.out", "//out/Debug/out2.out");
   target_bar.SetToolchain(setup.toolchain());
   ASSERT_TRUE(target_bar.OnResolved(&err));
 
   std::ostringstream ninja_out;
   std::ostringstream depfile_out;
   std::vector<const Settings*> all_settings = { setup.settings() };
   std::vector<const Target*> targets = { &target_foo, &target_bar };
+  std::vector<const Pool*> all_pools;
   NinjaBuildWriter writer(setup.build_settings(), all_settings,
-                          setup.toolchain(), targets, ninja_out, depfile_out);
+                          setup.toolchain(), targets, all_pools, ninja_out,
+                          depfile_out);
   ASSERT_FALSE(writer.Run(&err));
 
   const char expected_help_test[] =
       "Two or more targets generate the same output:\n"
       "  out2.out\n"
       "\n"
       "This is can often be fixed by changing one of the target names, or by \n"
       "setting an output_name on one of them.\n"
       "\n"
       "Collisions:\n"
       "  //foo:bar\n"
       "  //bar:bar\n";
 
   EXPECT_EQ(expected_help_test, err.help_text());
 }