[iOS] Enable Native Context Menu Flag by Default

Bug: 1110944
Change-Id: I83d2e15de5ef086c86a55c064159e7b75c69e251
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2611049Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Commit-Queue: Sebastien Lalancette <seblalancette@chromium.org>
Cr-Commit-Position: refs/heads/master@{#840602}

ios/chrome/browser/ui/ui_feature_flags.cc

@@ -31,8 +31,8 @@ const base::Feature kForceUnstackedTabstrip{"ForceUnstackedTabstrip",
 const base::Feature kTestFeature{"TestFeature",
                                  base::FEATURE_DISABLED_BY_DEFAULT};
 
-const base::Feature kEnableNativeContextMenus{
-    "EnableNativeContextMenus", base::FEATURE_DISABLED_BY_DEFAULT};
+const base::Feature kEnableNativeContextMenus{"EnableNativeContextMenus",
+                                              base::FEATURE_ENABLED_BY_DEFAULT};
 
 const base::Feature kEnableIOSManagedSettingsUI{
     "EnableIOSManagedSettingsUI", base::FEATURE_ENABLED_BY_DEFAULT};