Add field trial for ReduceAcceptLanguageHTTP

Change-Id: I44322f5584bd8be9b9e2014a0de70a4429bd5c94
Bug: 334954143,384488975
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6387641
Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Victor Tan <victortan@chromium.org>
Reviewed-by: Andrew Williams <awillia@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1437579}

chrome/browser/reduce_accept_language/reduce_accept_language_browsertest.cc

@@ -531,9 +531,9 @@ class ReduceAcceptLanguageBrowserTest : public policy::PolicyTest {
 class DisableFeatureReduceAcceptLanguageBrowserTest
     : public ReduceAcceptLanguageBrowserTest {
   void EnabledFeatures() override {
-    std::unique_ptr<base::FeatureList> feature_list(new base::FeatureList);
+    scoped_feature_list_.InitWithFeatures(
-    feature_list->InitFromCommandLine("", "ReduceAcceptLanguage");
+        {}, {network::features::kReduceAcceptLanguage,
-    scoped_feature_list_.InitWithFeatureList(std::move(feature_list));
+             network::features::kReduceAcceptLanguageHTTP});
   }
 };
 

content/browser/web_package/signed_exchange_request_handler_browsertest.cc

@@ -265,7 +265,8 @@ class SignedExchangeRequestHandlerBrowserTest
     // TODO(crbug.com/334954143) Fix the AcceptLanguage tests when turning on
     // the ReduceAcceptLanguage feature.
     scoped_feature_list_.InitWithFeatures(
-        {}, {network::features::kReduceAcceptLanguage});
+        {}, {network::features::kReduceAcceptLanguage,
+             network::features::kReduceAcceptLanguageHTTP});
     use_prefetch_ = GetParam();
   }
 

testing/variations/fieldtrial_testing_config.json

@@ -19618,6 +19618,25 @@
             ]
         }
     ],
+    "ReduceAcceptLanguageHTTP": [
+        {
+            "platforms": [
+                "android",
+                "chromeos",
+                "linux",
+                "mac",
+                "windows"
+            ],
+            "experiments": [
+                {
+                    "name": "Enabled",
+                    "enable_features": [
+                        "ReduceAcceptLanguageHTTP"
+                    ]
+                }
+            ]
+        }
+    ],
     "ReduceCpuUtilization2": [
         {
             "platforms": [