Add a flat_map container

base/BUILD.gn

 # 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.
 
 # HOW TO WRITE CONDITIONALS IN THIS FILE
 # ======================================
 #
 # In many other places, one would write a conditional that expresses all the
 # cases when a source file is used or unused, and then either add or subtract
 # it from the sources list in that case
@@ skipping 258 matching lines @@
     "callback_helpers.cc",
     "callback_helpers.h",
     "callback_internal.cc",
     "callback_internal.h",
     "callback_list.h",
     "cancelable_callback.h",
     "command_line.cc",
     "command_line.h",
     "compiler_specific.h",
     "containers/adapters.h",
+    "containers/flat_map.h",
     "containers/flat_set.h",
+    "containers/flat_tree.h",
     "containers/hash_tables.h",
     "containers/linked_list.h",
     "containers/mru_cache.h",
     "containers/small_map.h",
     "containers/stack_container.h",
     "cpu.cc",
     "cpu.h",
     "critical_closure.h",
     "critical_closure_internal_ios.mm",
 
@@ skipping 1625 matching lines @@
     "bind_unittest.cc",
     "bit_cast_unittest.cc",
     "bits_unittest.cc",
     "build_time_unittest.cc",
     "callback_helpers_unittest.cc",
     "callback_list_unittest.cc",
     "callback_unittest.cc",
     "cancelable_callback_unittest.cc",
     "command_line_unittest.cc",
     "containers/adapters_unittest.cc",
+    "containers/container_test_utils.h",
+    "containers/flat_map_unittest.cc",
     "containers/flat_set_unittest.cc",
+    "containers/flat_tree_unittest.cc",
     "containers/hash_tables_unittest.cc",
     "containers/linked_list_unittest.cc",
     "containers/mru_cache_unittest.cc",
     "containers/small_map_unittest.cc",
     "containers/stack_container_unittest.cc",
     "cpu_unittest.cc",
     "debug/activity_analyzer_unittest.cc",
     "debug/activity_tracker_unittest.cc",
     "debug/crash_logging_unittest.cc",
     "debug/debugger_unittest.cc",
@@ skipping 731 matching lines @@
 }
 
 fuzzer_test("base_json_correctness_fuzzer") {
   sources = [
     "json/correctness_fuzzer.cc",
   ]
   deps = [
     ":base",
   ]
 }