Add switches for language detection and translation logging.

Apply switches as previosuly discussed so we easily turn off
language detection logging or translation logging if something
goes wrong.

BUG=728491, 722679

Review-Url: https://codereview.chromium.org/2941953002
Cr-Commit-Position: refs/heads/master@{#481054}

chrome/browser/translate/chrome_translate_client.cc

@@ -7,6 +7,7 @@
 #include <memory>
 #include <vector>
 
+#include "base/feature_list.h"
 #include "base/logging.h"
 #include "base/path_service.h"
 #include "base/strings/string_split.h"
@@ -31,6 +32,7 @@
 #include "chrome/grit/theme_resources.h"
 #include "components/metrics/proto/translate_event.pb.h"
 #include "components/prefs/pref_service.h"
+#include "components/sync/driver/sync_driver_switches.h"
 #include "components/sync/protocol/user_event_specifics.pb.h"
 #include "components/sync/user_events/user_event_service.h"
 #include "components/translate/core/browser/language_model.h"
@@ -53,6 +55,7 @@
 #include "url/gurl.h"
 
 namespace {
+using base::FeatureList;
 using metrics::TranslateEventProto;
 
 TranslateEventProto::EventType BubbleResultToTranslateEvent(
@@ -79,6 +82,8 @@ TranslateEventProto::EventType BubbleResultToTranslateEvent(
 void LogLanguageDetectionEvent(
     const content::WebContents* const web_contents,
     const translate::LanguageDetectionDetails& details) {
+  if (!FeatureList::IsEnabled(switches::kSyncUserLanguageDetectionEvents))
+    return;
   auto* const profile =
       Profile::FromBrowserContext(web_contents->GetBrowserContext());
 
@@ -104,6 +109,8 @@ void LogLanguageDetectionEvent(
 
 void LogTranslateEvent(const content::WebContents* const web_contents,
                        const metrics::TranslateEventProto& translate_event) {
+  if (!FeatureList::IsEnabled(switches::kSyncUserTranslationEvents))
+    return;
   DCHECK(web_contents);
   auto* const profile =
       Profile::FromBrowserContext(web_contents->GetBrowserContext());

chrome/browser/translate/chrome_translate_client_unittest.cc

@@ -9,9 +9,11 @@
 #include "base/command_line.h"
 #include "base/memory/ref_counted.h"
 #include "base/run_loop.h"
+#include "base/test/scoped_feature_list.h"
 #include "chrome/browser/sync/profile_sync_service_factory.h"
 #include "chrome/browser/sync/user_event_service_factory.h"
 #include "chrome/test/base/chrome_render_view_host_test_harness.h"
+#include "components/sync/driver/sync_driver_switches.h"
 #include "components/sync/user_events/fake_user_event_service.h"
 #include "components/translate/core/common/language_detection_details.h"
 #include "content/public/browser/web_contents.h"
@@ -31,6 +33,9 @@ class ChromeTranslateClientTest : public ChromeRenderViewHostTestHarness {
         browser_sync::UserEventServiceFactory::GetInstance()
             ->SetTestingFactoryAndUse(browser_context(),
                                       &BuildFakeUserEventService));
+    scoped_feature_list_ = base::MakeUnique<base::test::ScopedFeatureList>();
+    scoped_feature_list_->InitAndEnableFeature(
+        switches::kSyncUserLanguageDetectionEvents);
   }
 
   void TearDown() override { ChromeRenderViewHostTestHarness::TearDown(); }
@@ -41,6 +46,7 @@ class ChromeTranslateClientTest : public ChromeRenderViewHostTestHarness {
   }
 
  private:
+  std::unique_ptr<base::test::ScopedFeatureList> scoped_feature_list_;
   syncer::FakeUserEventService* fake_user_event_service_;
 };