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

content/child/npapi/plugin_host.cc

Index: content/child/npapi/plugin_host.cc
diff --git a/content/child/npapi/plugin_host.cc b/content/child/npapi/plugin_host.cc
index f560061161b9ac302ac5fba2a259ea6ca17a4c2e..f5a04efaf5b437482f7036654b1116d9b6b25909 100644
--- a/content/child/npapi/plugin_host.cc
+++ b/content/child/npapi/plugin_host.cc
@@ -502,6 +502,8 @@
   // Variables:
   //    NPNVxDisplay (unix only)
   //    NPNVxtAppContext (unix only)
+  //    NPNVnetscapeWindow (win only) - Gets the native window on which the
+  //              plugin drawing occurs, returns HWND
   //    NPNVjavascriptEnabledBool:  tells whether Javascript is enabled
   //    NPNVasdEnabledBool:  tells whether SmartUpdate is enabled
   //    NPNVOfflineBool: tells whether offline-mode is enabled
@@ -549,6 +551,19 @@
       }
       break;
     }
+  #if !defined(OS_MACOSX)  // OS X doesn't have windowed plugins.
+    case NPNVnetscapeWindow: {
+      scoped_refptr<PluginInstance> plugin = FindInstance(id);
+      if (!plugin.get()) {
+        NOTREACHED();
+        return NPERR_INVALID_INSTANCE_ERROR;
+      }
+      gfx::PluginWindowHandle handle = plugin->window_handle();
+      *((void**)value) = (void*)handle;
+      rv = NPERR_NO_ERROR;
+      break;
+    }
+  #endif
     case NPNVjavascriptEnabledBool: {
       // yes, JS is enabled.
       *((void**)value) = (void*)1;