Add a device policy for specifying the release channel.

chrome/browser/policy/device_policy_cache.cc

Index: chrome/browser/policy/device_policy_cache.cc
diff --git a/chrome/browser/policy/device_policy_cache.cc b/chrome/browser/policy/device_policy_cache.cc
index bb9f5339146baade3d10c68e1751dbd27db7f0dd..10d320410aafa54312798f324f61b2da8204e6e2 100644
--- a/chrome/browser/policy/device_policy_cache.cc
+++ b/chrome/browser/policy/device_policy_cache.cc
@@ -9,6 +9,8 @@
 #include "base/logging.h"
 #include "base/task.h"
 #include "base/values.h"
+#include "chrome/browser/chromeos/cros/cros_library.h"
+#include "chrome/browser/chromeos/cros/update_library.h"
 #include "chrome/browser/chromeos/cros_settings_names.h"
 #include "chrome/browser/chromeos/login/ownership_service.h"
 #include "chrome/browser/chromeos/login/signed_settings_helper.h"
@@ -299,6 +301,16 @@ void DevicePolicyCache::DecodeDevicePolicy(
                        Value::CreateStringValue(container.proxy_bypass_list()));
     }
   }
+
+  if (policy.has_release_channel() &&
+      policy.release_channel().has_release_channel()) {
+    std::string channel = policy.release_channel().release_channel();
+    mandatory->Set(
+        kPolicyChromeOsReleaseChannel, Value::CreateStringValue(channel));
+    // TODO: We should probably set the release track somewhere else, but this
+    // policy is a work-in-progress (http://crosbug.com/15382).
+    chromeos::CrosLibrary::Get()->GetUpdateLibrary()->SetReleaseTrack(channel);
+  }
 }
 
 }  // namespace policy