Use icudat*.dat file on Mac

1. Set icu_use_data_file_flag to 1 in common.gypi
2. Add icudatl.dat to the resournce bundle list in
chrome_dll_bundle.gypi and content_shell.gypi
3. Move ICU_UTIL_DATA_IMPL to base.gyp

This CL has to be landed after
https://codereview.chromium.org/111723007/ is landed and rolled in. 
(done in https://codereview.chromium.org/118313004/ )

Note to perf-sheriff: This CL adds ~10MB to the resource bundle while cutting down the same amount from the Chrome executable/binary.  

BUG=72633
TEST=All the Mac builds (static, shared) go through and tests (e.g.
layout tests, base_unittests --gtest_filter=*String*, net_unittests
--gtest_filter=*IDN*) loading the ICU data pass.

Review URL: https://codereview.chromium.org/109013004

git-svn-id: http://src.chromium.org/svn/trunk/src/build@247404 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

common.gypi

@@ -1313,6 +1313,9 @@
           }],
         ],
       }],  # os_posix==1 and OS!="mac" and OS!="ios"
+      ['OS=="mac"', {
+        'icu_use_data_file_flag%': 1,
+      }],  # os=="mac"
       ['OS=="ios"', {
         'disable_nacl%': 1,
         'enable_background%': 0,
@@ -2214,17 +2217,6 @@
       ['use_udev==1', {
         'defines': ['USE_UDEV'],
       }],
-      ['icu_use_data_file_flag==1', {
-        'defines': ['ICU_UTIL_DATA_IMPL=ICU_UTIL_DATA_FILE'],
-      }, { # else icu_use_data_file_flag !=1
-        'conditions': [
-          ['OS=="win"', {
-            'defines': ['ICU_UTIL_DATA_IMPL=ICU_UTIL_DATA_SHARED'],
-          }, {
-            'defines': ['ICU_UTIL_DATA_IMPL=ICU_UTIL_DATA_STATIC'],
-          }],
-        ],
-      }],
       ['fastbuild!=0', {
         'xcode_settings': {
           'GCC_GENERATE_DEBUGGING_SYMBOLS': 'NO',