Functionality to allow blacklist and whitelist of custom schemes

components/policy/resources/policy_templates.json

Index: components/policy/resources/policy_templates.json
diff --git a/components/policy/resources/policy_templates.json b/components/policy/resources/policy_templates.json
index a876cd254d267bb4c7c9317ea31b3f21006a3042..191afca1b42ba622dc326ac912cba10dc09f36da 100644
--- a/components/policy/resources/policy_templates.json
+++ b/components/policy/resources/policy_templates.json
@@ -4304,7 +4304,7 @@
         'dynamic_refresh': True,
         'per_profile': True,
       },
-      'example_value': ['example.com', 'https://ssl.server.com', 'hosting.com/bad_path', 'https://server:8080/path', '.exact.hostname.com', 'file://*', '*'],
+      'example_value': ['example.com', 'https://ssl.server.com', 'hosting.com/bad_path', 'https://server:8080/path', '.exact.hostname.com', 'file://*', 'custom_scheme:*', '*'],
       'id': 103,
       'caption': '''Block access to a list of URLs''',
       'tags': ['filtering'],
@@ -4312,10 +4312,12 @@
 
       This policy prevents the user from loading web pages from blacklisted URLs. The blacklist provides a list of URL patterns that specify which URLs will be blacklisted.
 
+      A URL pattern has to be formatted according to https://www.chromium.org/administrators/url-blacklist-filter-format.
+
       Each URL pattern can either be a pattern for local files or a generic URL pattern. Local file patterns are of the format 'file://path', where path should be an absolute path to block. All file system locations for which that path is a prefix will be blocked.

[Thiemo Nagel, 2016/04/25 09:11:10]

Please remove duplications.  No need to re-phrase what is already explained in
the linked docs.

[igorcov, 2016/04/25 13:17:12]

Done.

 
       A generic URL pattern has the format 'scheme://host:port/path'.
-      If present, only the specified scheme will be blocked. If the scheme:// prefix is not specified, all schemes are blocked.
+      If present, only the specified scheme will be blocked. If the scheme:// prefix is not specified, all schemes are blocked. If a non-standard scheme is used, only the patterns 'scheme_name:*' and 'scheme_name://*' are accepted, matching all URLs with that scheme.
       The host is required and can be a hostname or an IP address. Subdomains of a hostname will also be blocked. To prevent blocking subdomains, include a '.' before the hostname. The special hostname '*' will block all domains.
       The optional port is a valid port number from 1 to 65535. If none is specified, all ports are blocked.
       If the optional path is specified, only paths with that prefix will be blocked.