Roll DEPS to pick up the latest CrOS system_api.

DEPS

 # This file is automatically processed to create .DEPS.git which is the file
 # that gclient uses under git.
 #
 # See http://code.google.com/p/chromium/wiki/UsingGit
 #
 # To test manually, run:
 #   python tools/deps2git/deps2git.py -o .DEPS.git
 #   gclient runhooks
 # DO NOT CHECK IN CHANGES TO .DEPS.git. It will be automatically updated by
 # a bot when you modify this one.
@@ skipping 460 matching lines @@
       "@e4e4656e9aa710f0617dab8746ab6116c0506ceb",
 
     # Used on Linux only. CrOS already has a copy.
     "src/third_party/cros_dbus_cplusplus/source":
       Var("chromiumos_git") + "/third_party/dbus-cplusplus.git" +
       "@e4120532bbf3ca9f743b0be1f539381a54d16867",
 
     # For Linux and Chromium OS.
     "src/third_party/cros_system_api":
       Var("chromiumos_git") + "/platform/system_api.git" +
-      "@6445c9773efbcbcbc4077c349f846b18c525b3eb",
+      "@9481a478cd2fea24ed70e81372529a613be1410d",
 
     # Note that this is different from Android's freetype repo.
     "src/third_party/freetype2/src":
       Var("chromium_git") + "/chromium/src/third_party/freetype2.git" +
       "@d699c2994ecc178c4ed05ac2086061b2034c2178",
 
     # Build tools for targeting ChromeOS.
     "src/third_party/chromite":
       Var("chromiumos_git") + "/chromite.git" +
       "@6637dcd35a8b9f02ba54d2a369118306cee88432",
@@ skipping 267 matching lines @@
     "pattern": ".",
     "action": ["python", "src/build/gyp_chromium"],
   },
   {
     # Check for landmines (reasons to clobber the build).
     "name": "landmines",
     "pattern": ".",
     "action": ["python", "src/build/landmines.py"],
   },
 ]