Browser Plugin: Remove dependency on NPAPI

content/browser/frame_host/render_widget_host_view_guest.cc

Index: content/browser/frame_host/render_widget_host_view_guest.cc
diff --git a/content/browser/frame_host/render_widget_host_view_guest.cc b/content/browser/frame_host/render_widget_host_view_guest.cc
index fb68070899d22ca5413bd1a08a920edd18f3d1be..924d7035eae126a20d3759674123b5e0e6a826df 100644
--- a/content/browser/frame_host/render_widget_host_view_guest.cc
+++ b/content/browser/frame_host/render_widget_host_view_guest.cc
@@ -367,7 +367,15 @@ void RenderWidgetHostViewGuest::CopyFromCompositingSurface(
 }
 
 void RenderWidgetHostViewGuest::SetBackgroundOpaque(bool opaque) {
-  platform_view_->SetBackgroundOpaque(opaque);
+  // Content embedders can toggle opaque backgrounds through this API.
+  // We plumb the value here so that BrowserPlugin updates its compositing
+  // state in response to this change. We also want to preserve this flag
+  // after recovering from a crash so we let BrowserPluginGuest store it.
+  if (!guest_)
+    return;
+  RenderWidgetHostViewBase::SetBackgroundOpaque(opaque);
+  host_->SetBackgroundOpaque(opaque);
+  guest_->SetContentsOpaque(opaque);
 }
 
 bool RenderWidgetHostViewGuest::LockMouse() {