Document interdependencies under ui/file_manager/file_manager.

The ChromeOS Gallery, video_player, and audio_player currently pick out
a collection of .js files from various places inside the folder structure
of the ChromeOS files App.

This CL documents where that occurs, with a view to move these, shared
files out to a shared "toolkit" folder higher up in the folder structure.
There is already a "common" folder, but it is within the Files app
subtree and hard to enforce via layering.

It uses GN's "visibility" on the closure targets to detect whether new
dependencies are added.

Bug: 879035
Cq-Include-Trybots: luci.chromium.try:closure_compilation
Change-Id: I6b134ccad20c22ad46372871ab488200d3cbafa1
Reviewed-on: https://chromium-review.googlesource.com/1188735
Commit-Queue: Trent Apted <tapted@chromium.org>
Reviewed-by: calamity <calamity@chromium.org>
Reviewed-by: Noel Gordon <noel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#590186}

third_party/closure_compiler/README.chromium

@@ -22,3 +22,4 @@ Local modifications:
 - Fix bug in js_binary.py causing it to drop externs.
 - Cache dependency subtrees in js_binary.py for a huge performance boost.
 - Add js_unit_tests.gni for generating .html files for running unit tests.
+- Forward target visibility in the js_library template.

third_party/closure_compiler/compile_js.gni

@@ -53,6 +53,7 @@ template("js_library") {
                              "externs_list",
                              "extra_sources",
                              "extra_deps",
+                             "visibility",
                            ])
     output_file = "$target_gen_dir/$target_name.js_library"
     outputs = [

ui/file_manager/file_manager/background/js/BUILD.gn

@@ -4,6 +4,22 @@
 
 import("//third_party/closure_compiler/compile_js.gni")
 
+# TODO(tapted): This folder should be restricted to file_manager, but related
+# apps currently depend on background_base, which depends on
+# volume_manager_factory, and that pulls in nearly everything else. For now,
+# document externally-exposed targets visible with this helper, and hide
+# transitive dependencies (but note those transitive dependencies should move
+# elsewhere too).
+related_apps = [
+  "//ui/file_manager/audio_player/*",
+  "//ui/file_manager/file_manager/*",
+  "//ui/file_manager/gallery/*",
+  "//ui/file_manager/video_player/*",
+]
+
+# Default to private.
+visibility = [ ":*" ]
+
 js_type_check("closure_compile") {
   deps = [
     ":app_window_wrapper",
@@ -60,6 +76,7 @@ js_library("closure_compile_externs") {
 }
 
 js_library("app_window_wrapper") {
+  visibility += related_apps
   deps = [
     ":app_windows",
     "../../common/js:async_util",
@@ -92,6 +109,7 @@ js_library("background") {
 }
 
 js_library("background_base") {
+  visibility += related_apps
   deps = [
     ":app_windows",
     ":volume_manager_factory",
@@ -209,6 +227,7 @@ js_library("media_scanner") {
 }
 
 js_library("mock_volume_manager") {
+  visibility += related_apps
   deps = [
     ":volume_info_impl",
     ":volume_info_list_impl",
@@ -234,6 +253,12 @@ js_library("task_queue") {
 }
 
 js_library("test_util_base") {
+  # TODO(tapted): Move this target to //ui/file_manager/base. It is used in the
+  # background page of all |related_apps|, but accessed via extension messaging.
+  # So it doesn't need to be visible as a closure dependency, except for the
+  # "unpacked" test framework.
+  visibility += [ "//ui/file_manager/file_manager/test/js:test_util" ]
+
   deps = [
     ":app_windows",
     "../../common/js:error_util",

ui/file_manager/file_manager/common/js/BUILD.gn

@@ -4,6 +4,9 @@
 
 import("//third_party/closure_compiler/compile_js.gni")
 
+# TODO(tapted): This entire folder should move to //ui/file_manager/base.
+visibility = [ "//ui/file_manager/*" ]
+
 js_type_check("closure_compile") {
   deps = [
     ":async_util",

ui/file_manager/file_manager/foreground/elements/BUILD.gn

@@ -4,6 +4,8 @@
 
 import("//third_party/closure_compiler/compile_js.gni")
 
+visibility = [ "//ui/file_manager/file_manager/foreground/*" ]
+
 js_type_check("closure_compile") {
   deps = [
     ":files_icon_button",
@@ -51,12 +53,18 @@ js_library("files_safe_media") {
 js_library("files_safe_media_webview_content") {
 }
 
+# TODO(tapted): Move this to //ui/file_manager/base.
 js_library("files_toast") {
+  visibility += [ "//ui/file_manager/gallery/*" ]
   externs_list = [ "$externs_path/web_animations.js" ]
 }
 
+# TODO(tapted): Move this to //ui/file_manager/base.
 js_library("files_toggle_ripple") {
+  visibility += [ "//ui/file_manager/gallery/*" ]
 }
 
+# TODO(tapted): Move this to //ui/file_manager/base.
 js_library("files_tooltip") {
+  visibility += [ "//ui/file_manager/gallery/*" ]
 }

ui/file_manager/file_manager/foreground/js/BUILD.gn

@@ -5,6 +5,11 @@
 import("//third_party/closure_compiler/compile_js.gni")
 import("//third_party/closure_compiler/js_unit_tests.gni")
 
+visibility = [
+  "//ui/file_manager/file_manager/foreground/*",
+  "//ui/file_manager/file_manager/test/js/*",
+]
+
 js_type_check("closure_compile_module") {
   deps = [
     ":actions_controller",
@@ -578,7 +583,9 @@ js_library("task_history") {
   ]
 }
 
+# TODO(tapted): Move this into //ui/file_manager/base.
 js_library("thumbnail_loader") {
+  visibility += [ "//ui/file_manager/gallery/*" ]
   deps = [
     "../../../image_loader:image_loader_client",
     "../../common/js:file_type",
@@ -606,7 +613,13 @@ js_library("toolbar_controller") {
   ]
 }
 
+# TODO(tapted): Move this to //ui/file_manager/base.
 js_library("volume_manager_wrapper") {
+  visibility += [
+    "//ui/file_manager/audio_player/*",
+    "//ui/file_manager/gallery/*",
+    "//ui/file_manager/video_player/*",
+  ]
   deps = [
     "../../../externs:file_manager_private",
     "../../common/js:async_util",
@@ -643,6 +656,7 @@ js_unit_tests("unit_tests") {
 }
 
 group("closure_compile") {
+  visibility += [ "*" ]
   deps = [
     ":closure_compile_module",
     ":unit_tests_type_check",

ui/file_manager/file_manager/foreground/js/metadata/BUILD.gn

@@ -4,6 +4,9 @@
 
 import("//third_party/closure_compiler/compile_js.gni")
 
+# TODO(tapted): This entire folder should move to //ui/file_manager/base.
+visibility = [ "//ui/file_manager/*" ]
+
 js_type_check("closure_compile") {
   deps = [
     ":byte_reader",

ui/file_manager/file_manager/foreground/js/ui/BUILD.gn

@@ -4,6 +4,8 @@
 
 import("//third_party/closure_compiler/compile_js.gni")
 
+visibility = [ "//ui/file_manager/file_manager/foreground/*" ]
+
 js_type_check("closure_compile") {
   deps = [
     ":actions_submenu",
@@ -261,13 +263,17 @@ js_library("file_tap_handler") {
   ]
 }
 
+# TODO(tapted): Move this into //ui/file_manager/base.
 js_library("files_alert_dialog") {
+  visibility += [ "//ui/file_manager/gallery/*" ]
   deps = [
     "//ui/webui/resources/js/cr/ui:dialogs",
   ]
 }
 
+# TODO(tapted): Move this into //ui/file_manager/base.
 js_library("files_confirm_dialog") {
+  visibility += [ "//ui/file_manager/gallery/*" ]
   deps = [
     "//ui/webui/resources/js/cr/ui:dialogs",
   ]
@@ -319,6 +325,9 @@ js_library("multi_profile_share_dialog") {
 }
 
 js_library("progress_center_panel") {
+  # The progress_center on the background page maintains a list of panels.
+  visibility += [ "//ui/file_manager/file_manager/background/*" ]
+
   deps = [
     "..:progress_center_item_group",
     "../../../common/js:progress_center_common",
@@ -349,7 +358,9 @@ js_library("search_box") {
   ]
 }
 
+# TODO(tapted): Move this into //ui/file_manager/base.
 js_library("share_dialog") {
+  visibility += [ "//ui/file_manager/gallery/*" ]
   deps = [
     ":file_manager_dialog_base",
     "..:share_client",

ui/file_manager/file_manager/test/BUILD.gn

@@ -45,6 +45,9 @@ js_type_check("closure_compile") {
   ]
 }
 
+# Remaining targets in this file are private.
+visibility = [ ":*" ]
+
 js_library("closure_compile_externs") {
   sources = []
   externs_list = [

ui/file_manager/file_manager/test/js/BUILD.gn

@@ -4,6 +4,8 @@
 
 import("//third_party/closure_compiler/compile_js.gni")
 
+visibility = [ "//ui/file_manager/file_manager/*" ]
+
 js_library("chrome_api_test_impl") {
 }