Add a feature flag for the product review reply button

Author: rachelmcr

Experiments/Experiments/DefaultFeatureFlagService.swift

@@ -37,6 +37,8 @@ public struct DefaultFeatureFlagService: FeatureFlagService {
             return true
         case .orderCreationSearchCustomers:
             return buildConfig == .localDeveloper || buildConfig == .alpha
+        case .replyToProductReviews:
+            return buildConfig == .localDeveloper || buildConfig == .alpha
         default:
             return true
         }

Experiments/Experiments/FeatureFlag.swift

@@ -77,4 +77,8 @@ public enum FeatureFlag: Int {
     /// Enables the Search Customers functionality in the Order Creation screen
     ///
     case orderCreationSearchCustomers
+
+    /// Enables replying to product reviews
+    ///
+    case replyToProductReviews
 }

WooCommerce/Classes/ViewRelated/Reviews/Cells/NoteDetailsCommentTableViewCell.swift

@@ -131,6 +131,17 @@ final class NoteDetailsCommentTableViewCell: UITableViewCell {
         }
     }
 
+    /// Indicates if the Reply Button is enabled (or not!)
+    ///
+    var isReplyEnabled: Bool {
+        get {
+            return replyButton.isHidden
+        }
+        set {
+            replyButton.isHidden = !newValue
+        }
+    }
+
     /// Title: Usually displays the Author's Name.
     ///
     var titleText: String? {

WooCommerce/Classes/ViewRelated/Reviews/ReviewDetailsViewController.swift

@@ -2,6 +2,7 @@ import UIKit
 import Yosemite
 import Gridicons
 import SafariServices
+import Experiments
 
 
 // MARK: - ReviewDetailsViewController
@@ -44,13 +45,16 @@ final class ReviewDetailsViewController: UIViewController {
     ///
     private var rows = [Row]()
 
+    private let featureFlagService: FeatureFlagService
+
     /// Designated Initializer
     ///
-    init(productReview: ProductReview, product: Product?, notification: Note?) {
+    init(productReview: ProductReview, product: Product?, notification: Note?, featureFlagService: FeatureFlagService = ServiceLocator.featureFlagService) {
         self.productReview = productReview
         self.siteID = productReview.siteID
         self.product = product
         self.notification = notification
+        self.featureFlagService = featureFlagService
         super.init(nibName: nil, bundle: nil)
     }
 
@@ -332,6 +336,7 @@ private extension ReviewDetailsViewController {
         commentCell.isTrashEnabled    = true
         commentCell.isSpamEnabled     = true
         commentCell.isApproveSelected = productReview.status == .approved
+        commentCell.isReplyEnabled    = featureFlagService.isFeatureFlagEnabled(.replyToProductReviews)
 
         let reviewID = productReview.reviewID
         let reviewSiteID = productReview.siteID