Componentize sad_tab

components/sad_tab/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-# GYP version: components/dom_distiller.gyp:dom_distiller_webui
-static_library("webui") {
+import("//build/config/ui.gni")
+
+static_library("sad_tab") {
   sources = [
-    "dom_distiller_handler.cc",
-    "dom_distiller_handler.h",
-    "dom_distiller_ui.cc",
-    "dom_distiller_ui.h",
+    "sad_tab.cc",
+    "sad_tab.h",
+    "sad_tab_client.h",
+    "sad_tab_helper.cc",
+    "sad_tab_helper.h",
+    "sad_tab_types.h",
+    "url_constants.cc",
+    "url_constants.h",
   ]
 
   deps = [
     "//base",
-    "//components/dom_distiller/core",
-    "//components/dom_distiller/core/proto",
     "//components/resources",
     "//components/strings",
     "//content/public/browser",
-    "//skia",
-    "//sync",
+    "//ui/base",
+    "//url",
   ]
+
+  if (toolkit_views) {
+    sources += [
+      "views/sad_tab_view.cc",
+      "views/sad_tab_view.h",
+    ]
+    deps += [
+      "//ui/views",
+    ]
+  }
 }