[EoS] Add country code to the request for the catalog.

The country code comes from the first place in the following list with a
non-empty country code:
* Field Trial parameter "country_override", configurable by Finch server
* Finch permanent country, which is updated when the Finch configs are
  updated (by default once per Chrome version). Permanent country may
  not be available in the first run of Chrome.
* Finch latest country, which is available on every run of Chrome.

Bug: 867488
Change-Id: I0e407a50a4020882152dda85935ecf843a000cb0
Reviewed-on: https://chromium-review.googlesource.com/c/1256110
Commit-Queue: Justin DeWitt <dewittj@chromium.org>
Reviewed-by: Peter Williamson <petewil@chromium.org>
Cr-Commit-Position: refs/heads/master@{#595978}

chrome/browser/android/explore_sites/explore_sites_fetcher.cc

@@ -4,6 +4,7 @@
 
 #include "chrome/browser/android/explore_sites/explore_sites_fetcher.h"
 
+#include <string>
 #include <utility>
 
 #include "base/bind.h"
@@ -17,8 +18,10 @@
 #include "chrome/browser/android/explore_sites/catalog.pb.h"
 #include "chrome/browser/android/explore_sites/explore_sites_types.h"
 #include "chrome/browser/android/explore_sites/url_util.h"
+#include "chrome/browser/browser_process.h"
 #include "chrome/browser/net/chrome_accept_language_settings.h"
 #include "chrome/common/channel_info.h"
+#include "components/variations/service/variations_service.h"
 #include "components/version_info/version_info.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/storage_partition.h"
@@ -39,6 +42,27 @@ namespace explore_sites {
 
 namespace {
 
+std::string GetCountry() {
+  std::string manually_set_variation_country =
+      base::GetFieldTrialParamValueByFeature(chrome::android::kExploreSites,
+                                             "country_override");
+  if (!manually_set_variation_country.empty())
+    return manually_set_variation_country;
+
+  variations::VariationsService* variations_service =
+      g_browser_process->variations_service();
+  if (variations_service) {
+    std::string country = variations_service->GetStoredPermanentCountry();
+    if (!country.empty())
+      return country;
+    country = variations_service->GetLatestCountry();
+    if (!country.empty())
+      return country;
+  }
+
+  return "DEFAULT";
+}
+
 // Content type needed in order to communicate with the server in binary
 // proto format.
 const char kRequestContentType[] = "application/x-protobuf";
@@ -68,33 +92,30 @@ constexpr net::NetworkTrafficAnnotationTag traffic_annotation =
 std::unique_ptr<ExploreSitesFetcher> ExploreSitesFetcher::CreateForGetCatalog(
     Callback callback,
     const std::string catalog_version,
-    const std::string country_code,
     const std::string accept_languages,
     scoped_refptr<network::SharedURLLoaderFactory> loader_factory) {
   GURL url = GetCatalogURL();
   return base::WrapUnique(
       new ExploreSitesFetcher(std::move(callback), url, catalog_version,
-                              country_code, accept_languages, loader_factory));
+                              accept_languages, loader_factory));
 }
 
 std::unique_ptr<ExploreSitesFetcher>
 ExploreSitesFetcher::CreateForGetCategories(
     Callback callback,
     const std::string catalog_version,
-    const std::string country_code,
     const std::string accept_languages,
     scoped_refptr<network::SharedURLLoaderFactory> loader_factory) {
   GURL url = GetCategoriesURL();
   return base::WrapUnique(
       new ExploreSitesFetcher(std::move(callback), url, catalog_version,
-                              country_code, accept_languages, loader_factory));
+                              accept_languages, loader_factory));
 }
 
 ExploreSitesFetcher::ExploreSitesFetcher(
     Callback callback,
     const GURL& url,
     const std::string catalog_version,
-    const std::string country_code,
     const std::string accept_languages,
     scoped_refptr<network::SharedURLLoaderFactory> loader_factory)
     : callback_(std::move(callback)),
@@ -109,9 +130,10 @@ ExploreSitesFetcher::ExploreSitesFetcher(
                          version.components()[3],  // Patch
                          channel_name.c_str());
   GURL final_url =
-      net::AppendOrReplaceQueryParameter(url, "country_code", country_code);
+      net::AppendOrReplaceQueryParameter(url, "country_code", GetCountry());
   final_url = net::AppendOrReplaceQueryParameter(final_url, "version_token",
                                                  catalog_version);
+  DVLOG(1) << "Final URL: " << final_url.spec();
 
   auto resource_request = std::make_unique<network::ResourceRequest>();
   resource_request->url = final_url;

chrome/browser/android/explore_sites/explore_sites_fetcher.h

@@ -33,7 +33,6 @@ class ExploreSitesFetcher {
   static std::unique_ptr<ExploreSitesFetcher> CreateForGetCatalog(
       Callback callback,
       const std::string catalog_version,
-      const std::string country_code,
       const std::string accept_languages,
       scoped_refptr<network::SharedURLLoaderFactory> loader_factory);
 
@@ -41,7 +40,6 @@ class ExploreSitesFetcher {
   static std::unique_ptr<ExploreSitesFetcher> CreateForGetCategories(
       Callback callback,
       const std::string catalog_version,
-      const std::string country_code,
       const std::string accept_languages,
       scoped_refptr<network::SharedURLLoaderFactory> loader_factory);
 
@@ -52,7 +50,6 @@ class ExploreSitesFetcher {
       Callback callback,
       const GURL& url,
       const std::string catalog_version,
-      const std::string country_code,
       const std::string accept_languages,
       scoped_refptr<network ::SharedURLLoaderFactory> loader_factory);
 

chrome/browser/android/explore_sites/explore_sites_fetcher_unittest.cc

@@ -4,11 +4,19 @@
 
 #include "chrome/browser/android/explore_sites/explore_sites_fetcher.h"
 
+#include <map>
+
 #include "base/message_loop/message_loop.h"
+#include "base/metrics/field_trial.h"
+#include "base/metrics/field_trial_params.h"
 #include "base/test/bind_test_util.h"
 #include "base/test/mock_callback.h"
+#include "base/test/mock_entropy_provider.h"
+#include "base/test/scoped_feature_list.h"
 #include "base/test/test_mock_time_task_runner.h"
+#include "chrome/browser/android/chrome_feature_list.h"
 #include "chrome/browser/android/explore_sites/catalog.pb.h"
+#include "chrome/browser/android/explore_sites/explore_sites_feature.h"
 #include "chrome/browser/android/explore_sites/explore_sites_types.h"
 #include "net/http/http_request_headers.h"
 #include "net/http/http_status_code.h"
@@ -43,6 +51,25 @@ class ExploreSitesFetcherTest : public testing::Test {
   ExploreSitesRequestStatus RunFetcherWithData(const std::string& response_data,
                                                std::string* data_received);
 
+  void SetUpExperimentOption(std::string country_code) {
+    const std::string kTrialName = "trial_name";
+    const std::string kGroupName = "group_name";
+
+    scoped_refptr<base::FieldTrial> trial =
+        base::FieldTrialList::CreateFieldTrial(kTrialName, kGroupName);
+
+    std::map<std::string, std::string> params = {
+        {"country_override", country_code}};
+    base::AssociateFieldTrialParams(kTrialName, kGroupName, params);
+
+    std::unique_ptr<base::FeatureList> feature_list =
+        std::make_unique<base::FeatureList>();
+    feature_list->RegisterFieldTrialOverride(
+        chrome::android::kExploreSites.name,
+        base::FeatureList::OVERRIDE_ENABLE_FEATURE, trial.get());
+    scoped_feature_list_.InitWithFeatureList(std::move(feature_list));
+  }
+
   network::ResourceRequest last_resource_request;
 
  private:
@@ -64,6 +91,8 @@ class ExploreSitesFetcherTest : public testing::Test {
   std::unique_ptr<std::string> last_data_;
   base::MessageLoopForIO message_loop_;
   scoped_refptr<base::TestMockTimeTaskRunner> task_runner_;
+  std::unique_ptr<base::FieldTrialList> field_trial_list_;
+  base::test::ScopedFeatureList scoped_feature_list_;
 };
 
 ExploreSitesFetcher::Callback ExploreSitesFetcherTest::StoreResult() {
@@ -88,6 +117,8 @@ void ExploreSitesFetcherTest::SetUp() {
         EXPECT_TRUE(request.url.is_valid() && !request.url.is_empty());
         last_resource_request = request;
       }));
+  field_trial_list_ = std::make_unique<base::FieldTrialList>(
+      std::make_unique<base::MockEntropyProvider>());
 }
 
 ExploreSitesRequestStatus ExploreSitesFetcherTest::RunFetcherWithNetError(
@@ -160,7 +191,7 @@ ExploreSitesRequestStatus ExploreSitesFetcherTest::RunFetcher(
     base::OnceCallback<void(void)> respond_callback,
     std::string* data_received) {
   std::unique_ptr<ExploreSitesFetcher> fetcher =
-      ExploreSitesFetcher::CreateForGetCatalog(StoreResult(), "123", "KE",
+      ExploreSitesFetcher::CreateForGetCatalog(StoreResult(), "123",
                                                kAcceptLanguages,
                                                test_shared_url_loader_factory_);
 
@@ -226,7 +257,20 @@ TEST_F(ExploreSitesFetcherTest, Success) {
 
   EXPECT_EQ(last_resource_request.url.spec(),
             "https://exploresites-pa.googleapis.com/v1/"
-            "getcatalog?country_code=KE&version_token=123");
+            "getcatalog?country_code=DEFAULT&version_token=123");
+}
+
+TEST_F(ExploreSitesFetcherTest, DefaultCountry) {
+  SetUpExperimentOption("KZ");
+  std::string data;
+  EXPECT_EQ(ExploreSitesRequestStatus::kSuccess,
+            RunFetcherWithData("Any data.", &data));
+  EXPECT_FALSE(data.empty());
+  EXPECT_EQ(data, "Any data.");
+
+  EXPECT_EQ(last_resource_request.url.spec(),
+            "https://exploresites-pa.googleapis.com/v1/"
+            "getcatalog?country_code=KZ&version_token=123");
 }
 
 TEST_F(ExploreSitesFetcherTest, TestHeaders) {

chrome/browser/android/explore_sites/explore_sites_service_impl.cc

@@ -79,14 +79,12 @@ void ExploreSitesServiceImpl::UpdateCatalogFromNetwork(
 
   // TODO(petewil): Eventually get the catalog version from DB.
   std::string catalog_version = "";
-  // TODO(petewil): Eventually get the country code from somewhere.
-  std::string country_code = "KE";
 
   // Create a fetcher and start fetching the protobuf (async).
   explore_sites_fetcher_ = ExploreSitesFetcher::CreateForGetCatalog(
       base::BindOnce(&ExploreSitesServiceImpl::OnCatalogFetched,
                      weak_ptr_factory_.GetWeakPtr(), std::move(callback)),
-      catalog_version, country_code, accept_languages, url_loader_factory_);
+      catalog_version, accept_languages, url_loader_factory_);
 }
 
 void ExploreSitesServiceImpl::OnCatalogFetched(