Add manifest.json to Flash output for Mac.

chrome/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("//build/buildflag_header.gni")
 import("//build/config/chrome_build.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/features.gni")
 import("//build/config/locales.gni")
 import("//build/config/sanitizers/sanitizers.gni")
@@ skipping 764 matching lines @@
     }
   } else {
     group("chrome_framework_plugins") {
     }
   }
 
   if (is_chrome_branded) {
     bundle_data("flash_player_plugin") {
       sources = [
         "$root_out_dir/PepperFlash/PepperFlashPlayer.plugin",
+        "$root_out_dir/PepperFlash/manifest.json",
       ]
       outputs = [
         "{{bundle_root_dir}}/Internet Plug-Ins/PepperFlash/{{source_file_part}}",
       ]
       public_deps = [
         "//third_party/adobe/flash:flapper_binaries",
       ]
     }
 
     bundle_data("widevine_cdm_library_binaries") {
@@ skipping 958 matching lines @@
       "//chrome/app/theme/$branding_path_component/product_logo_48.png",
       "//chrome/tools/build/linux/chrome-wrapper",
       "//third_party/xdg-utils/scripts/xdg-mime",
       "//third_party/xdg-utils/scripts/xdg-settings",
     ]
     outputs = [
       "$root_out_dir/{{source_file_part}}",
     ]
   }
 }