Add a hang monitor for Pepper plugins

chrome/browser/ui/tab_contents/tab_contents_wrapper.h

Index: chrome/browser/ui/tab_contents/tab_contents_wrapper.h
diff --git a/chrome/browser/ui/tab_contents/tab_contents_wrapper.h b/chrome/browser/ui/tab_contents/tab_contents_wrapper.h
index bb48bf953e8c24fa389d675809564f6936125d01..d573d6210b8fdfadb347ff908e0a8b5b0cc02da8 100644
--- a/chrome/browser/ui/tab_contents/tab_contents_wrapper.h
+++ b/chrome/browser/ui/tab_contents/tab_contents_wrapper.h
@@ -31,6 +31,7 @@ class ExternalProtocolObserver;
 class FaviconTabHelper;
 class FindTabHelper;
 class HistoryTabHelper;
+class HungPluginTabHelper;
 class InfoBarTabHelper;
 class OmniboxSearchHint;
 class PasswordManager;
@@ -148,6 +149,9 @@ class TabContentsWrapper : public content::WebContentsObserver {
   FaviconTabHelper* favicon_tab_helper() { return favicon_tab_helper_.get(); }
   FindTabHelper* find_tab_helper() { return find_tab_helper_.get(); }
   HistoryTabHelper* history_tab_helper() { return history_tab_helper_.get(); }
+  HungPluginTabHelper* hung_plugin_tab_helper() {
+    return hung_plugin_tab_helper_.get();
+  }
   InfoBarTabHelper* infobar_tab_helper() { return infobar_tab_helper_.get(); }
 
 #if defined(ENABLE_ONE_CLICK_SIGNIN)
@@ -229,6 +233,7 @@ class TabContentsWrapper : public content::WebContentsObserver {
   scoped_ptr<FaviconTabHelper> favicon_tab_helper_;
   scoped_ptr<FindTabHelper> find_tab_helper_;
   scoped_ptr<HistoryTabHelper> history_tab_helper_;
+  scoped_ptr<HungPluginTabHelper> hung_plugin_tab_helper_;
   scoped_ptr<InfoBarTabHelper> infobar_tab_helper_;
 
   // PasswordManager and its delegate. The delegate must outlive the manager,