Use a direct include of strings headers in base/.

BUG=247723
TEST=none
TBR=ben@chromium.org

Review URL: https://chromiumcodereview.appspot.com/16745002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@205530 0039d316-1c4b-4281-b951-d872f2087c98

• base/android/jni_array.h[diff]
• base/base_paths_mac.mm[diff]
• base/command_line.cc[diff]
• base/containers/hash_tables.h[diff]
• base/containers/stack_container.h[diff]
• base/debug/crash_logging.cc[diff]
• base/debug/debugger_posix.cc[diff]
• base/debug/profiler.cc[diff]
• base/debug/stack_trace_win.cc[diff]
• base/debug/trace_event_android.cc[diff]
• base/debug/trace_event_impl.cc[diff]
• base/debug/trace_event_impl.h[diff]
• base/debug/trace_event_unittest.cc[diff]
• base/environment.cc[diff]
• base/file_util.cc[diff]
• base/file_util.h[diff]
• base/file_util_mac.mm[diff]
• base/file_util_posix.cc[diff]
• base/file_util_win.cc[diff]
• base/file_version_info.h[diff]
• base/files/file_path.cc[diff]
• base/files/file_path.h[diff]
• base/files/file_path_watcher_browsertest.cc[diff]
• base/files/file_path_watcher_kqueue.cc[diff]
• base/files/memory_mapped_file_win.cc[diff]
• base/guid.cc[diff]
• base/guid_posix.cc[diff]
• base/guid_win.cc[diff]