Revert of Remove a bunch of NPAPI quirks and related support code

content/child/BUILD.gn

Index: content/child/BUILD.gn
diff --git a/content/child/BUILD.gn b/content/child/BUILD.gn
index b63cf6fa08757a12fe66eb2ff7bd3825c799041a..c2cb0b37c818e8ca292bf2f1c59116e6ee04fbda 100644
--- a/content/child/BUILD.gn
+++ b/content/child/BUILD.gn
@@ -84,7 +84,11 @@
         "npapi/webplugin_delegate_impl_mac.mm",
       ]
     } else if (is_win) {
-      sources -= [ "npapi/webplugin_delegate_impl_win.cc" ]
+      sources -= [
+        "npapi/webplugin_delegate_impl_win.cc",
+        "npapi/webplugin_ime_win.cc",
+        "npapi/webplugin_ime_win.h",
+      ]
     } else if (is_android) {
       sources -= [ "npapi/webplugin_delegate_impl_android.cc" ]
     }