Enable some parts of base that were previously disabled in base_untrusted

base/base.gyp

Index: base/base.gyp
diff --git a/base/base.gyp b/base/base.gyp
index 13379817b1c0b9ac7b1aec656e2ec89c64b54ced..48cbde3a13cbb1a1509f64bbda8d4e8ed35859a3 100644
--- a/base/base.gyp
+++ b/base/base.gyp
@@ -209,8 +209,6 @@
         'third_party/xdg_user_dirs/xdg_user_dir_lookup.cc',
         'third_party/xdg_user_dirs/xdg_user_dir_lookup.h',
         'auto_reset.h',
-        'base64.cc',
-        'base64.h',
         'event_recorder.h',
         'event_recorder_stubs.cc',
         'event_recorder_win.cc',
@@ -235,13 +233,9 @@
         'message_pump_mac.mm',
         'metrics/field_trial.cc',
         'metrics/field_trial.h',
-        'string16.cc',
-        'string16.h',
         'sync_socket.h',
         'sync_socket_win.cc',
         'sync_socket_posix.cc',
-        'time_mac.cc',
-        'time_posix.cc',
       ],
     },
     {
@@ -331,6 +325,10 @@
         'win/pe_image.cc',
         'win/pe_image.h',
       ],
+      'sources!': [
+        # base64.cc depends on modp_b64.
+        'base64.cc',
+      ],
       'include_dirs': [
         '..',
       ],
@@ -832,6 +830,10 @@
           'defines': [
             '<@(nacl_win64_defines)',
           ],
+          'sources!': [
+            # base64.cc depends on modp_b64.
+            'base64.cc',
+          ],
           'configurations': {
             'Common_Base': {
               'msvs_target_platform': 'x64',