Add Brotli to Accept Encoding header for secure DRP requests

components/data_reduction_proxy/core/common/data_reduction_proxy_params_unittest.cc

Index: components/data_reduction_proxy/core/common/data_reduction_proxy_params_unittest.cc
diff --git a/components/data_reduction_proxy/core/common/data_reduction_proxy_params_unittest.cc b/components/data_reduction_proxy/core/common/data_reduction_proxy_params_unittest.cc
index e849b0df9f6ddd78e96dc648496a82c2af363a73..46a56f5b32bf160949ae2d511a37e9f9585c8254 100644
--- a/components/data_reduction_proxy/core/common/data_reduction_proxy_params_unittest.cc
+++ b/components/data_reduction_proxy/core/common/data_reduction_proxy_params_unittest.cc
@@ -193,6 +193,46 @@ TEST_F(DataReductionProxyParamsTest, IsClientConfigEnabled) {
   }
 }
 
+TEST_F(DataReductionProxyParamsTest, IsBrotliAcceptEncodingEnabled) {
+  const struct {
+    std::string test_case;
+    std::string trial_group_value;
+    bool expected;
+  } tests[] = {
+      {
+          "Nothing set", "", true,
+      },
+      {
+          "Enabled in experiment", "Enabled", true,
+      },
+      {
+          "Alternate enabled in experiment", "Enabled_Other", true,
+      },
+      {
+          "Control in experiment", "Control", true,
+      },
+      {
+          "Disabled in experiment", "Disabled", false,
+      },
+      {
+          "Disabled in experiment", "Disabled_Other", false,
+      },
+      {
+          "disabled in experiment lower case", "disabled", true,
+      },
+  };
+
+  for (const auto& test : tests) {
+    base::FieldTrialList field_trial_list(nullptr);
+    if (!test.trial_group_value.empty()) {
+      ASSERT_TRUE(base::FieldTrialList::CreateFieldTrial(
+          "DataReductionProxyBrotliAcceptEncoding", test.trial_group_value));
+    }
+    EXPECT_EQ(test.expected, params::IsBrotliAcceptEncodingEnabled())
+        << test.test_case;
+  }
+}
+
 TEST_F(DataReductionProxyParamsTest, AreServerExperimentsEnabled) {
   const struct {
     std::string test_case;