libchrome: Add files needed by some veyron variants on Chrome OS

These files are needed for Chrome IPC. These will be compiled on
Chrome OS, so no impact on AOSP.

BUG: 26772882
TEST: make -j32 for dragonboard
      ./build_packages on CrOS for various boards.

Change-Id: Ibca0a04692a59f245cab2d5c9707cff109ca144f
diff --git a/SConstruct b/SConstruct
index b316900..5e00390 100644
--- a/SConstruct
+++ b/SConstruct
@@ -57,6 +57,8 @@
                 files/file_util_linux.cc
                 files/file_util_posix.cc
                 files/important_file_writer.cc
+                files/memory_mapped_file.cc
+                files/memory_mapped_file_posix.cc
                 files/scoped_file.cc
                 files/scoped_temp_dir.cc
                 guid.cc
@@ -97,6 +99,7 @@
                 pending_task.cc
                 pickle.cc
                 posix/file_descriptor_shuffle.cc
+                posix/global_descriptors.cc
                 posix/safe_strerror.cc
                 posix/unix_domain_socket_linux.cc
                 process/internal_linux.cc
@@ -139,6 +142,7 @@
                 synchronization/lock.cc
                 synchronization/lock_impl_posix.cc
                 synchronization/waitable_event_posix.cc
+                synchronization/waitable_event_watcher_posix.cc
                 sync_socket_posix.cc
                 sys_info.cc
                 sys_info_chromeos.cc