Upgrade ICU to 54.1

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 116 matching lines @@
   'src/third_party/colorama/src':
    Var('chromium_git') + '/external/colorama.git' + '@' + '799604a1041e9b3bc5d2789ecbd7e8db2e18e6b8',
 
   'src/third_party/trace-viewer':
    Var('chromium_git') + '/external/trace-viewer.git' + '@' + 'a9802a1384185f9c7ee250ce67d3d24d07b11141',
 
   'src/third_party/WebKit':
    Var('chromium_git') + '/chromium/blink.git' + '@' +  Var('webkit_revision'),
 
   'src/third_party/icu':
-   Var('chromium_git') + '/chromium/deps/icu.git' + '@' + '4e3266f32c62d30a3f9e2232a753c60129d1e670',
+   Var('chromium_git') + '/chromium/deps/icu.git' + '@' + '8d46830a11d9d1ee7815dbf217c840e74afb8e7e',
 
   'src/third_party/libexif/sources':
    Var('chromium_git') + '/chromium/deps/libexif/sources.git' + '@' + 'ed98343daabd7b4497f97fda972e132e6877c48a',
 
   'src/third_party/hunspell':
    Var('chromium_git') + '/chromium/deps/hunspell.git' + '@' + 'c956c0e97af00ef789afb2f64d02c9a5a50e6eb1',
 
   'src/third_party/hunspell_dictionaries':
    Var('chromium_git') + '/chromium/deps/hunspell_dictionaries.git' + '@' + '94eb94ce85661b54bb3c27bedeff5428b4a2798e', # from svn revision 292714
 
@@ skipping 629 matching lines @@
     # corresponding .py files have already been deleted.
     'name': 'remove_stale_pyc_files',
     'pattern': 'src/tools/.*\\.py',
     'action': [
         'python',
         'src/tools/remove_stale_pyc_files.py',
         'src/tools',
     ],
   },
 ]