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

content/browser/renderer_host/render_widget_host_view_aura.cc

Index: content/browser/renderer_host/render_widget_host_view_aura.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
index 448c6b454858a1d85b29f69e08668a9c77148cd8..7608c7b652a396f5c3024a5c581397edf1b714de 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -1075,6 +1075,15 @@
 void RenderWidgetHostViewAura::SetParentNativeViewAccessible(
     gfx::NativeViewAccessible accessible_parent) {
 }
+
+gfx::NativeViewId RenderWidgetHostViewAura::GetParentForWindowlessPlugin()
+    const {
+  if (legacy_render_widget_host_HWND_) {
+    return reinterpret_cast<gfx::NativeViewId>(
+        legacy_render_widget_host_HWND_->hwnd());
+  }
+  return NULL;
+}
 #endif
 
 bool RenderWidgetHostViewAura::HasAcceleratedSurface(
@@ -2577,8 +2586,10 @@
   delegated_frame_host_->WasResized();
 #if defined(OS_WIN)
   // Create the legacy dummy window which corresponds to the bounds of the
-  // webcontents. It is needed for accessibility and for scrolling to work in
-  // legacy drivers for trackpoints/trackpads, etc.
+  // webcontents. This will be passed as the container window for windowless
+  // plugins.
+  // Additonally the legacy dummy window is needed for accessibility and for
+  // scrolling to work in legacy drivers for trackpoints/trackpads, etc.
   if (!legacy_window_destroyed_ && GetNativeViewId()) {
     if (!legacy_render_widget_host_HWND_) {
       legacy_render_widget_host_HWND_ = LegacyRenderWidgetHostHWND::Create(