Remove content/public/plugin and chrome/plugin

content/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.
 
 import("//tools/grit/grit_rule.gni")
 import("//build/config/nacl/config.gni")
 
 # Applied by targets internal to content.
 config("content_implementation") {
   defines = [ "CONTENT_IMPLEMENTATION" ]
@@ skipping 44 matching lines @@
 # //content/browser target only in non-component builds (when there are no
 # linking problems) for when check is enabled.
 
 if (!is_nacl_nonsfi) {
   content_shared_components = [
     "//content/gpu:gpu_sources",
     "//content/public/browser:browser_sources",
     "//content/public/child:child_sources",
     "//content/public/gpu:gpu_sources",
     "//content/public/common:common_sources",
-    "//content/public/plugin:plugin_sources",
     "//content/public/renderer:renderer_sources",
     "//content/public/utility:utility_sources",
   ]
 
   if (enable_plugins) {
     content_shared_components +=
         [ "//content/ppapi_plugin:ppapi_plugin_sources" ]
   }
 }
 
@@ skipping 55 matching lines @@
     sources = [
       "app/sandbox_helper_win.cc",
       "public/app/sandbox_helper_win.h",
     ]
 
     deps = [
       "//sandbox",
     ]
   }
 }