Add Chromoting curtain-mode policy.

chrome/app/policy/policy_templates.json

Index: chrome/app/policy/policy_templates.json
diff --git a/chrome/app/policy/policy_templates.json b/chrome/app/policy/policy_templates.json
index 79eb0cac272502d98915231e3e0ab054732c95e7..2909de0bef20c089f4c9ea68356e68dc02153085 100644
--- a/chrome/app/policy/policy_templates.json
+++ b/chrome/app/policy/policy_templates.json
@@ -112,7 +112,7 @@
 #   persistent IDs for all fields (but not for groups!) are needed. These are
 #   specified by the 'id' keys of each policy. NEVER CHANGE EXISTING IDs,
 #   because doing so would break the deployed wire format!
-#   For your editing convenience: highest ID currently used: 156
+#   For your editing convenience: highest ID currently used: 157
 #
 # Placeholders:
 #   The following placeholder strings are automatically substituted:
@@ -503,6 +503,21 @@
 
           Remote access clients are not affected by this policy setting. They will always use 'chromoting-client.talkgadget.google.com' to access the TalkGadget.''',
         },
+        {
+          'name': 'RemoteAccessHostRequireCurtain',
+          'type': 'main',
+          'schema': { 'type': 'boolean' },
+          'supported_on': ['chrome.*:23-', 'chrome_os:0.23-'],
+          'features': {'dynamic_refresh': True},
+          'example_value': False,
+          'id': 157,
+          'caption': '''Enable curtaining of remote access hosts.''',
+          'desc': '''Enables curtaining of remote access hosts while a connection is in progress.
+
+          If this setting is enabled, then hosts' physical input and output devices are disabled while a remote connection is in progress.
+
+          If this setting is disabled or not set, then both local and remote users can interact with the host when it is being shared.''',
+        },
       ],
     },
     {