[Sky] Fix iOS build breaks

sky/shell/BUILD.gn

 # Copyright 2015 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.
 
 common_deps = [
   "//base",
   "//base:i18n",
   "//build/config/sanitizers:deps",
   "//dart/runtime:libdart",
   "//mojo/common",
@@ skipping 146 matching lines @@
         "ios/main_ios.mm",
         "ios/platform_service_provider_ios.cc",
         "ios/platform_view_ios.h",
         "ios/platform_view_ios.mm",
         "ios/sky_app_delegate.h",
         "ios/sky_app_delegate.mm",
         "ios/sky_surface.h",
         "ios/sky_surface.mm",
         "ios/sky_view_controller.h",
         "ios/sky_view_controller.mm",
-        "platform_view.cc",
       ]
 
       deps = common_deps + [
                ":common",
                "//sky/services/ns_net",
              ]
     }
 
     deps = [
       ":$scaffolding_target",
@@ skipping 13 matching lines @@
     ]
 
     deps = common_deps + [
              ":common",
              "//sky/services/testing:interfaces",
            ]
   }
 } else {
   assert(false, "Unsupported platform")
 }