Reland: Make separate net and url GN targets with and without ICU

net/net_common.gypi

Index: net/net_common.gypi
diff --git a/net/net_common.gypi b/net/net_common.gypi
index 62b471c680d6786012bc24e47880c5eb55e97e94..b9e7910772537e2e6754aa66aad4e76244b4925d 100644
--- a/net/net_common.gypi
+++ b/net/net_common.gypi
@@ -90,27 +90,10 @@
       # TODO(mmenke):  Should probably get rid of the dependency on
       # net_resources in this case (It's used in net_util, to format
       # directory listings.  Also used outside of net/).
-      'sources!': [
-        'base/directory_lister.cc',
-        'base/directory_lister.h',
-        'url_request/file_protocol_handler.cc',
-        'url_request/file_protocol_handler.h',
-        'url_request/url_request_file_dir_job.cc',
-        'url_request/url_request_file_dir_job.h',
-        'url_request/url_request_file_job.cc',
-        'url_request/url_request_file_job.h',
-      ],
+      'sources!': ['<@(net_file_support_sources)']
     }],
     ['disable_ftp_support==1', {
-      'sources/': [
-        ['exclude', '^ftp/'],
-      ],
-      'sources!': [
-        'url_request/ftp_protocol_handler.cc',
-        'url_request/ftp_protocol_handler.h',
-        'url_request/url_request_ftp_job.cc',
-        'url_request/url_request_ftp_job.h',
-      ],
+      'sources!': ['<@(net_ftp_support_sources)']
     }],
     ['enable_built_in_dns==1', {
       'defines': [
@@ -297,9 +280,7 @@
         ],
     }],
     [ 'enable_websockets != 1', {
-        'sources/': [
-          ['exclude', '^websockets/'],
-        ],
+        'sources!': ['<@(net_websockets_sources)']
     }],
     [ 'enable_mdns != 1', {
         'sources!' : [