Add a device policy for specifying the release channel.

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 602669a62988cb36ca086e415f0f7b8f2d4083a9..5c7f7a1fd4eea2dd20b3dd956d16348af238b10a 100644
--- a/chrome/app/policy/policy_templates.json
+++ b/chrome/app/policy/policy_templates.json
@@ -94,7 +94,7 @@
 #   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: 90
+#   For your editing convenience: highest ID currently used: 91
 #
 # Placeholders:
 #   The following placeholder strings are automatically substituted:
@@ -1565,6 +1565,34 @@
 
       Setting this policy overrides the default value of 3 hours. Valid values for this policy are in the range from 1800000 (30 minutes) to 86400000 (1 day). Any values not in this range will be clamped to the respective boundary.''',
     },
+    {
+      'name': 'ChromeOsReleaseChannel',
+      'type': 'string-enum',
+      'items': [
+        {
+          'name': 'Stable',
+          'value': 'stable-channel',
+          'caption': '''Stable channel'''
+        },
+        {
+          'name': 'Beta',
+          'value': 'beta-channel',
+          'caption': '''Beta channel'''
+        },
+        {
+          'name': 'Dev - Unstable',
+          'value': 'dev-channel',
+          'caption': '''Dev channel (may be unstable)'''
+        }
+      ],
+      'supported_on': ['chrome_os:1.0-'],
+      'device_only': True,
+      'features': {'dynamic_refresh': 1},
+      'example_value': 'stable-channel',
+      'id': 91,
+      'caption': '''Release channel''',
+      'desc': '''Specifies the release channel that this device should be locked to. This policy is a work in progress; currently, the user can still change the release channel even if it's specified by the policy.'''
+    },
 
   ],
   'messages': {