Add gn args and BUILDFLAGS for OfflinePages, instead on relying on is_android and is_official_build.

chrome/browser/android/chrome_jni_registrar.cc

Index: chrome/browser/android/chrome_jni_registrar.cc
diff --git a/chrome/browser/android/chrome_jni_registrar.cc b/chrome/browser/android/chrome_jni_registrar.cc
index 8d4a2ab182b2f93a5a70697501d634d5240ec67b..eff99b91ad91012d68cc7be621a010982bed726d 100644
--- a/chrome/browser/android/chrome_jni_registrar.cc
+++ b/chrome/browser/android/chrome_jni_registrar.cc
@@ -182,6 +182,7 @@
 #include "components/gcm_driver/instance_id/android/component_jni_registrar.h"
 #include "components/invalidation/impl/android/component_jni_registrar.h"
 #include "components/offline_items_collection/core/android/offline_content_aggregator_bridge.h"
+#include "components/offline_pages/features/features.h"

[dewittj, 2017/05/11 17:03:40]

nit: why add this now?

[Dmitry Titov, 2017/05/11 17:35:04]

It defines the BUILDFLAG(ENABLE_OFFLINE_PAGES_HARNESS) used below. This seems to
be a regular practice for features.h files to build those and include
unconditionally - see printing/features in this file for example.

 #include "components/payments/content/android/component_jni_registrar.h"
 #include "components/policy/core/browser/android/component_jni_registrar.h"
 #include "components/safe_browsing_db/android/jni_registrar.h"
@@ -208,7 +209,7 @@
 #include "third_party/gvr-android-sdk/native_callbacks_jni.h"
 #endif
 
-#if !defined(OFFICIAL_BUILD)
+#if BUILDFLAG(ENABLE_OFFLINE_PAGES_HARNESS)
 #include "chrome/browser/android/offline_pages/evaluation/offline_page_evaluation_bridge.h"
 #endif
 
@@ -354,7 +355,7 @@ static base::android::RegistrationMethod kChromeRegisteredMethods[] = {
     {"OfflinePageBridge", offline_pages::android::RegisterOfflinePageBridge},
     {"OfflinePageDownloadBridge",
      offline_pages::android::OfflinePageDownloadBridge::Register},
-#if !defined(OFFICIAL_BUILD)
+#if BUILDFLAG(ENABLE_OFFLINE_PAGES_HARNESS)
     {"OfflinePageEvaluationBridge",
      offline_pages::android::OfflinePageEvaluationBridge::Register},
 #endif