Appease jschuh@ by adding a field trial to move 'plugin' to blockable mixed content.

content/browser/renderer_host/render_view_host_impl.cc

Index: content/browser/renderer_host/render_view_host_impl.cc
diff --git a/content/browser/renderer_host/render_view_host_impl.cc b/content/browser/renderer_host/render_view_host_impl.cc
index 3363c5145d5073b0496c15a23a5933a3ec549962..73da6b4f4a80e1c8ea461b939c33a6b18350c71c 100644
--- a/content/browser/renderer_host/render_view_host_impl.cc
+++ b/content/browser/renderer_host/render_view_host_impl.cc
@@ -528,6 +528,11 @@ WebPreferences RenderViewHostImpl::ComputeWebkitPrefs() {
   prefs.strictly_block_blockable_mixed_content =
       blockable_mixed_content_group == "StrictlyBlockBlockableMixedContent";
 
+  const std::string plugin_mixed_content_status =
+      base::FieldTrialList::FindFullName("PluginMixedContentStatus");
+  prefs.block_mixed_plugin_content =
+      plugin_mixed_content_status == "BlockableMixedContent";
+
   prefs.v8_cache_options = GetV8CacheOptions();
 
   GetContentClient()->browser()->OverrideWebkitPrefs(this, &prefs);