Roll cros_system_api to for power_manager: [S,G]etBacklightsForcedOff constants

DEPS

 # This file is used to manage the dependencies of the Chromium src repo. It is
 # used by gclient to determine what version of each dependency to check out, and
 # where.
 #
 # For more information, please refer to the official documentation:
 #   https://sites.google.com/a/chromium.org/dev/developers/how-tos/get-the-code
 #
 # When adding a new dependency, please update the top-level .gitignore file
 # to list the dependency's destination directory.
 #
@@ skipping 361 matching lines @@
   'unix': {
     # Linux, really.
     'src/third_party/xdg-utils':
       Var('chromium_git') + '/chromium/deps/xdg-utils.git' + '@' + 'd80274d5869b17b8c9067a1022e4416ee7ed5e0d',
 
     'src/third_party/lss':
       Var('chromium_git') + '/linux-syscall-support.git' + '@' + Var('lss_revision'),
 
     # For Linux and Chromium OS.
     'src/third_party/cros_system_api':
-      Var('chromium_git') + '/chromiumos/platform/system_api.git' + '@' + '1b7b261e7757d49fd9035c12e17704e6fe956032',
+      Var('chromium_git') + '/chromiumos/platform/system_api.git' + '@' + 'd726d6e8e26c53689f9d4d732d6650ec296722e3',
 
     # Note that this is different from Android's freetype repo.
     'src/third_party/freetype2/src':
       Var('chromium_git') + '/chromium/src/third_party/freetype2.git' + '@' + 'fc1532a7c4c592f24a4c1a0261d2845524ca5cff',
 
     'src/third_party/freetype-android/src':
       Var('chromium_git') + '/chromium/src/third_party/freetype2.git' + '@' + Var('freetype_android_revision'),
 
     # Build tools for Chrome OS. Note: This depends on third_party/pyelftools.
     'src/third_party/chromite':
@@ skipping 626 matching lines @@
 ]
 
 recursedeps = [
   # buildtools provides clang_format, libc++, and libc++abi
   'src/buildtools',
   # android_tools manages the NDK.
   'src/third_party/android_tools',
   # ANGLE manages DEPS that it also owns the build files for, such as dEQP.
   ("src/third_party/angle", "DEPS.chromium"),
 ]