Add field trial handling to enable the Data Reduction Proxy config service.

components/data_reduction_proxy/core/browser/data_reduction_proxy_config_service_client_unittest.cc

Index: components/data_reduction_proxy/core/browser/data_reduction_proxy_config_service_client_unittest.cc
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_config_service_client_unittest.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_config_service_client_unittest.cc
index e9fc3d1ffcca4f59094d706453795ab077619bec..0e952d7dc63dc1356f7009ec07722eafbfc825b7 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_config_service_client_unittest.cc
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_config_service_client_unittest.cc
@@ -4,11 +4,13 @@
 
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_config_service_client.h"
 
+#include <map>
 #include <string>
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/metrics/field_trial.h"
 #include "base/time/tick_clock.h"
 #include "base/values.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_config_test_utils.h"
@@ -20,6 +22,7 @@
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_pref_names.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_switches.h"
 #include "components/data_reduction_proxy/proto/client_config.pb.h"
+#include "components/variations/variations_associated_data.h"
 #include "net/http/http_response_headers.h"
 #include "net/proxy/proxy_server.h"
 #include "net/socket/socket_test_util.h"
@@ -68,6 +71,9 @@ const char kSerializedOrigin[] = "https://serialized.net:443";
 const char kSerializedFallback[] = "serialized.net:80";
 const char kSerializedSessionKey[] = "SerializedSessionKey";
 
+const char kConfigServiceFieldTrial[] = "DataReductionProxyConfigService";
+const char kConfigServiceURLParam[] = "url";
+
 }  // namespace
 
 namespace data_reduction_proxy {
@@ -326,26 +332,81 @@ TEST_F(DataReductionProxyConfigServiceClientTest, ConfigDisabled) {
 
 TEST_F(DataReductionProxyConfigServiceClientTest, GetConfigServiceURL) {
   const struct {
+    std::string trial_group_value;
+    std::string trial_url_param;
+  } variations[] = {
+      {
+       "Enabled", "http://enabled.config-service/",
+      },
+      {
+       "Disabled", "http://disabled.config-service/",
+      },
+      {
+       "EnabledOther", "http://other.config-service/",
+      },
+  };
+
+  variations::testing::ClearAllVariationParams();
+  for (const auto& variation : variations) {
+    std::map<std::string, std::string> variation_params;
+    variation_params[kConfigServiceURLParam] = variation.trial_url_param;
+    ASSERT_TRUE(variations::AssociateVariationParams(
+        kConfigServiceFieldTrial, variation.trial_group_value,
+        variation_params));
+  }
+
+  const struct {
+    std::string test_case;
     std::string flag_value;
+    std::string trial_group_value;
     GURL expected;
   } tests[] = {
       {
-       "", GURL(),
+       "Nothing set", "", "", GURL(),
+      },
+      {
+       "Only command line set",
+       "http://commandline.config-service/",
+       "",
+       GURL("http://commandline.config-service/"),
+      },
+      {
+       "Enabled group", "", "Enabled", GURL("http://enabled.config-service/"),
+      },
+      {
+       "Disabled group",
+       "",
+       "Disabled",
+       GURL("http://disabled.config-service/"),
+      },
+      {
+       "Alternate enabled group",
+       "",
+       "EnabledOther",
+       GURL("http://other.config-service/"),
       },
       {
-       "http://configservice.chrome-test.com",
-       GURL("http://configservice.chrome-test.com"),
+       "Command line precedence",
+       "http://commandline.config-service/",
+       "Enabled",
+       GURL("http://commandline.config-service/"),
       },
   };
 
   for (const auto& test : tests) {
     // Reset all flags.
     base::CommandLine::ForCurrentProcess()->InitFromArgv(0, NULL);
-    base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
-        switches::kDataReductionProxyConfigURL, test.flag_value);
-    EXPECT_EQ(test.expected,
-              DataReductionProxyConfigServiceClient::GetConfigServiceURL(
-                  *base::CommandLine::ForCurrentProcess()));
+    if (!test.flag_value.empty()) {
+      base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
+          switches::kDataReductionProxyConfigURL, test.flag_value);
+    }
+    base::FieldTrialList field_trial_list(nullptr);
+    if (!test.trial_group_value.empty()) {
+      base::FieldTrialList::CreateFieldTrial(kConfigServiceFieldTrial,
+                                             test.trial_group_value);
+    }
+    EXPECT_EQ(test.expected, DataReductionProxyParams::GetConfigServiceURL())
+        << test.test_case;
   }
 }