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

chrome/browser/BUILD.gn

Index: chrome/browser/BUILD.gn
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index 9092afd6fba4d816c792b766028c1583b0d52bf7..eb9e85b634fc4524b8f82e678b7519626caef930 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -8,6 +8,7 @@ import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//build/split_static_library.gni")
 import("//chrome/common/features.gni")
+import("//components/offline_pages/features/features.gni")
 import("//components/os_crypt/features.gni")
 import("//components/spellcheck/spellcheck_build_features.gni")
 import("//device/vr/features/features.gni")
@@ -1515,14 +1516,7 @@ split_static_library("browser") {
     "//components/ntp_snippets",
     "//components/ntp_tiles",
     "//components/offline_items_collection/core",
-    "//components/offline_pages/content",
-    "//components/offline_pages/content/background_loader",
-    "//components/offline_pages/core",
-    "//components/offline_pages/core/background:background_offliner",
-    "//components/offline_pages/core/downloads:offline_pages_ui_adapter",
-    "//components/offline_pages/core/prefetch",
-    "//components/offline_pages/core/recent_tabs",
-    "//components/offline_pages/core/request_header:request_header",
+    "//components/offline_pages/features:features",
     "//components/omnibox/browser",
     "//components/os_crypt",
     "//components/packed_ct_ev_whitelist",
@@ -2107,6 +2101,77 @@ split_static_library("browser") {
       "//third_party/adobe/flash:flapper_version_h",
     ]
   }
+
+  if (enable_offline_pages) {
+    sources += [
+      "android/offline_pages/background_loader_offliner.cc",

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

I wonder if it makes sense to just have BUILD.gn in android/offline_pages/ that
defines a source_set.

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

Perhaps. However most of the sources in c/b are included directly into this
target, so it is more consistent with the rest of this file to do this...

+      "android/offline_pages/background_loader_offliner.h",
+      "android/offline_pages/background_scheduler_bridge.cc",
+      "android/offline_pages/background_scheduler_bridge.h",
+      "android/offline_pages/downloads/offline_page_download_bridge.cc",
+      "android/offline_pages/downloads/offline_page_download_bridge.h",
+      "android/offline_pages/downloads/offline_page_infobar_delegate.cc",
+      "android/offline_pages/downloads/offline_page_infobar_delegate.h",
+      "android/offline_pages/downloads/offline_page_notification_bridge.cc",
+      "android/offline_pages/downloads/offline_page_notification_bridge.h",
+      "android/offline_pages/downloads/resource_throttle.cc",
+      "android/offline_pages/downloads/resource_throttle.h",
+      "android/offline_pages/offline_page_bookmark_observer.cc",
+      "android/offline_pages/offline_page_bookmark_observer.h",
+      "android/offline_pages/offline_page_bridge.cc",
+      "android/offline_pages/offline_page_bridge.h",
+      "android/offline_pages/offline_page_info_handler.cc",
+      "android/offline_pages/offline_page_info_handler.h",
+      "android/offline_pages/offline_page_mhtml_archiver.cc",
+      "android/offline_pages/offline_page_mhtml_archiver.h",
+      "android/offline_pages/offline_page_model_factory.cc",
+      "android/offline_pages/offline_page_model_factory.h",
+      "android/offline_pages/offline_page_request_interceptor.cc",
+      "android/offline_pages/offline_page_request_interceptor.h",
+      "android/offline_pages/offline_page_request_job.cc",
+      "android/offline_pages/offline_page_request_job.h",
+      "android/offline_pages/offline_page_tab_helper.cc",
+      "android/offline_pages/offline_page_tab_helper.h",
+      "android/offline_pages/offline_page_utils.cc",
+      "android/offline_pages/offline_page_utils.h",
+      "android/offline_pages/offliner_helper.cc",
+      "android/offline_pages/offliner_helper.h",
+      "android/offline_pages/prefetch/prefetch_background_task.cc",
+      "android/offline_pages/prefetch/prefetch_background_task.h",
+      "android/offline_pages/prerender_adapter.cc",
+      "android/offline_pages/prerender_adapter.h",
+      "android/offline_pages/prerendering_loader.cc",
+      "android/offline_pages/prerendering_loader.h",
+      "android/offline_pages/prerendering_offliner.cc",
+      "android/offline_pages/prerendering_offliner.h",
+      "android/offline_pages/recent_tab_helper.cc",
+      "android/offline_pages/recent_tab_helper.h",
+      "android/offline_pages/request_coordinator_factory.cc",
+      "android/offline_pages/request_coordinator_factory.h",
+    ]
+    deps += [
+      "//components/offline_pages/content",
+      "//components/offline_pages/content/background_loader",
+      "//components/offline_pages/core",
+      "//components/offline_pages/core/background:background_offliner",
+      "//components/offline_pages/core/downloads:offline_pages_ui_adapter",
+      "//components/offline_pages/core/prefetch",
+      "//components/offline_pages/core/recent_tabs",
+      "//components/offline_pages/core/request_header:request_header",
+    ]
+  }
+
+  # Used to build test harness locally. The harness is used manually to
+  # produce multiple offline pages to evaluate quality of the snapshots.
+  if (enable_offline_pages_harness) {
+    sources += [
+      "android/offline_pages/evaluation/evaluation_test_scheduler.cc",

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

Are there no tests for these files? If there are tests then they won't build
without the flag.  It makes sense to have tests for these files, at least to
ensure they can compile.

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

I don't know if there are tests for these, and adding tests if they are not
there would be out of scope for this CL. Note the offline_pages unittests are
still unconditionally included into unittest build on all platforms, and pull in
the core via deps. We might deal with this later as it seems orthogonal.

[romax, 2017/05/11 18:09:20]

Unfortunately there's no test for these since they're not supposed to be part of
production (i think it's a bad excuse). But on a big picture I guess there is a
chance to rewrite the whole test harness since we're  targeting downloaded pages
when using it.
TBH i don't even care if it will compile, since it won't compile without setting
the flag manually, and we are the only people using it (at least for now).

+      "android/offline_pages/evaluation/evaluation_test_scheduler.h",
+      "android/offline_pages/evaluation/offline_page_evaluation_bridge.cc",
+      "android/offline_pages/evaluation/offline_page_evaluation_bridge.h",
+    ]
+  }
+
   if (safe_browsing_mode != 0) {
     # "Safe Browsing Basic" files used for safe browsing in full mode
     # (safe_browsing=1) and mobile (=2)
@@ -2868,50 +2933,6 @@ split_static_library("browser") {
       "android/ntp/recent_tabs_page_prefs.h",
       "android/ntp/suggestions_event_reporter_bridge.cc",
       "android/ntp/suggestions_event_reporter_bridge.h",
-      "android/offline_pages/background_loader_offliner.cc",
-      "android/offline_pages/background_loader_offliner.h",
-      "android/offline_pages/background_scheduler_bridge.cc",
-      "android/offline_pages/background_scheduler_bridge.h",
-      "android/offline_pages/downloads/offline_page_download_bridge.cc",
-      "android/offline_pages/downloads/offline_page_download_bridge.h",
-      "android/offline_pages/downloads/offline_page_infobar_delegate.cc",
-      "android/offline_pages/downloads/offline_page_infobar_delegate.h",
-      "android/offline_pages/downloads/offline_page_notification_bridge.cc",
-      "android/offline_pages/downloads/offline_page_notification_bridge.h",
-      "android/offline_pages/downloads/resource_throttle.cc",
-      "android/offline_pages/downloads/resource_throttle.h",
-      "android/offline_pages/offline_page_bookmark_observer.cc",
-      "android/offline_pages/offline_page_bookmark_observer.h",
-      "android/offline_pages/offline_page_bridge.cc",
-      "android/offline_pages/offline_page_bridge.h",
-      "android/offline_pages/offline_page_info_handler.cc",
-      "android/offline_pages/offline_page_info_handler.h",
-      "android/offline_pages/offline_page_mhtml_archiver.cc",
-      "android/offline_pages/offline_page_mhtml_archiver.h",
-      "android/offline_pages/offline_page_model_factory.cc",
-      "android/offline_pages/offline_page_model_factory.h",
-      "android/offline_pages/offline_page_request_interceptor.cc",
-      "android/offline_pages/offline_page_request_interceptor.h",
-      "android/offline_pages/offline_page_request_job.cc",
-      "android/offline_pages/offline_page_request_job.h",
-      "android/offline_pages/offline_page_tab_helper.cc",
-      "android/offline_pages/offline_page_tab_helper.h",
-      "android/offline_pages/offline_page_utils.cc",
-      "android/offline_pages/offline_page_utils.h",
-      "android/offline_pages/offliner_helper.cc",
-      "android/offline_pages/offliner_helper.h",
-      "android/offline_pages/prefetch/prefetch_background_task.cc",
-      "android/offline_pages/prefetch/prefetch_background_task.h",
-      "android/offline_pages/prerender_adapter.cc",
-      "android/offline_pages/prerender_adapter.h",
-      "android/offline_pages/prerendering_loader.cc",
-      "android/offline_pages/prerendering_loader.h",
-      "android/offline_pages/prerendering_offliner.cc",
-      "android/offline_pages/prerendering_offliner.h",
-      "android/offline_pages/recent_tab_helper.cc",
-      "android/offline_pages/recent_tab_helper.h",
-      "android/offline_pages/request_coordinator_factory.cc",
-      "android/offline_pages/request_coordinator_factory.h",
       "android/omnibox/answers_image_bridge.cc",
       "android/omnibox/answers_image_bridge.h",
       "android/omnibox/autocomplete_controller_android.cc",
@@ -3204,16 +3225,6 @@ split_static_library("browser") {
         "supervised_user/child_accounts/child_account_service_android.h",
       ]
     }
-
-    # Used for testing only, should not be shipped to end users.
-    if (!is_official_build) {
-      sources += [
-        "android/offline_pages/evaluation/evaluation_test_scheduler.cc",
-        "android/offline_pages/evaluation/evaluation_test_scheduler.h",
-        "android/offline_pages/evaluation/offline_page_evaluation_bridge.cc",
-        "android/offline_pages/evaluation/offline_page_evaluation_bridge.h",
-      ]
-    }
   } else {
     # Non-Android.
     sources += [