kiosk: Add allow_kiosk_app_control_chrome_version policy

BUG=577765

Review URL: https://codereview.chromium.org/1590103004

Cr-Commit-Position: refs/heads/master@{#370713}

chrome/browser/chromeos/policy/proto/chrome_device_policy.proto

@@ -648,6 +648,12 @@ message DisplayRotationDefaultProto {
   optional Rotation display_rotation_default = 1;
 }
 
+// Settings that control whether to allow Chrome to be pinned to a specific
+// version according to the auto-launched kiosk app’s requirement.
+message AllowKioskAppControlChromeVersionProto {
+  optional bool allow_kiosk_app_control_chrome_version = 1 [default = false];
+}
+
 message ChromeDeviceSettingsProto {
   optional DevicePolicyRefreshRateProto device_policy_refresh_rate = 1;
   optional UserWhitelistProto user_whitelist = 2;
@@ -692,4 +698,6 @@ message ChromeDeviceSettingsProto {
       login_screen_domain_auto_complete = 37;
   optional DeviceLogUploadSettingsProto device_log_upload_settings = 38;
   optional DisplayRotationDefaultProto display_rotation_default = 39;
+  optional AllowKioskAppControlChromeVersionProto
+      allow_kiosk_app_control_chrome_version = 40;
 }