Add chrome_elf and cloud_print to "gn check"

.gn

 # This file is used by the GN meta build system to find the root of the source
 # tree and to set startup options. For documentation on the values set in this
 # file, run "gn help dotfile" at the command line.
 
 # The location of the build configuration file.
 buildconfig = "//build/config/BUILDCONFIG.gn"
 
 # The secondary source root is a parallel directory tree where
 # GN build files are placed when they can not be placed directly
 # in the source tree, e.g. for third party source trees.
@@ skipping 10 matching lines @@
   "//blink/*",
   "//breakpad/*",
   "//build/*",
   "//cc/*",
 
   #"//chrome/*",  # Epic number of errors.
   "//chrome/common/*",
   "//chrome/installer/*",
   "//chrome/third_party/mozilla_security_manager/*",
   "//chromecast/*",
-
-  # TODO(brettw): Fix http://crbug.com/460828 and uncomment the following
-  # line.
-  #"//chrome_elf/*",
-  #"//cloud_print/*",
-
+  "//chrome_elf/*",
+  "//cloud_print/*",
   "//components/*",
 
   #"//content/*",  # A whole lot of errors.
   "//content/public/common:result_codes",
   "//content/public/common:static_switches",
   "//courgette/*",
   "//crypto/*",
   "//data/*",
   "//dbus/*",
 
@@ skipping 149 matching lines @@
   "//tools/gn/format_test_data/055.golden",
   "//tools/gn/function_exec_script.cc",
   "//tools/gn/gn.gyp",
   "//tools/gn/input_conversion.cc",
   "//tools/gn/misc/emacs/gn.el",
   "//tools/gn/misc/vim/syntax/gn.vim",
   "//tools/gn/setup.cc",
   "//ui/accessibility/BUILD.gn",
   "//ui/views/BUILD.gn",
 ]