Enabled NewPassKitDownload feature by default.

Disabled this feature for unit test which tests old code.

Bug: 787943
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: I2aba8bcca42197bc18b390181099ba664f171646
Reviewed-on: https://chromium-review.googlesource.com/828284Reviewed-by: Gregory Chatzinoff <gchatz@chromium.org>
Commit-Queue: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#524440}

ios/web/features.mm

@@ -11,7 +11,7 @@ const base::Feature kSlimNavigationManager{"SlimNavigationManager",
                                            base::FEATURE_DISABLED_BY_DEFAULT};
 
 const base::Feature kNewPassKitDownload{"NewPassKitDownload",
-                                        base::FEATURE_DISABLED_BY_DEFAULT};
+                                        base::FEATURE_ENABLED_BY_DEFAULT};
 
 const base::Feature kNewFileDownload{"NewFileDownload",
                                      base::FEATURE_DISABLED_BY_DEFAULT};

ios/web/web_state/crw_pass_kit_downloader_unittest.mm

@@ -8,6 +8,8 @@
 
 #include <memory>
 
+#include "base/test/scoped_feature_list.h"
+#include "ios/web/public/features.h"
 #include "ios/web/public/test/web_test.h"
 #include "net/base/net_errors.h"
 #include "net/http/http_response_headers.h"
@@ -39,6 +41,7 @@ class CRWPassKitDownloaderTest : public WebTest {
  protected:
   void SetUp() override {
     WebTest::SetUp();
+    feature_list_.InitAndDisableFeature(web::features::kNewPassKitDownload);
     completion_handler_success_ = false;
     fetcher_factory_.reset(new net::TestURLFetcherFactory());
     downloader_ = [[CRWPassKitDownloader alloc]
@@ -76,6 +79,8 @@ class CRWPassKitDownloaderTest : public WebTest {
   // set from the completion handler based on whether actual data is equal to
   // expected data.
   bool completion_handler_success_;
+
+  base::test::ScopedFeatureList feature_list_;
 };
 
 // Tests case where CRWPassKitDownloader successfully downloads data.