Convert the PluginService interface to be an async wrapper around PluginList.

chrome/browser/pdf_unsupported_feature.cc

Index: chrome/browser/pdf_unsupported_feature.cc
diff --git a/chrome/browser/pdf_unsupported_feature.cc b/chrome/browser/pdf_unsupported_feature.cc
index c5460f810dd4523426eaf3e4b12fc9531aa736f1..e6784e0b23b97f9b8bb758877832a6114abc6827 100644
--- a/chrome/browser/pdf_unsupported_feature.cc
+++ b/chrome/browser/pdf_unsupported_feature.cc
@@ -30,11 +30,8 @@
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/image/image.h"
 #include "webkit/plugins/npapi/plugin_group.h"
-#include "webkit/plugins/npapi/plugin_list.h"
-#include "webkit/plugins/webplugininfo.h"
 
 using webkit::npapi::PluginGroup;
-using webkit::npapi::PluginList;
 using webkit::WebPluginInfo;
 
 namespace {
@@ -387,7 +384,7 @@ void PDFHasUnsupportedFeature(TabContentsWrapper* tab) {
 
   PluginGroup* reader_group = NULL;
   std::vector<PluginGroup> plugin_groups;
-  PluginList::Singleton()->GetPluginGroups(false, &plugin_groups);
+  PluginService::GetInstance()->GetCachedPluginGroups(&plugin_groups);
   for (size_t i = 0; i < plugin_groups.size(); ++i) {
     if (plugin_groups[i].GetGroupName() == reader_group_name) {
       reader_group = &plugin_groups[i];