Introduce runtime.onSuspendCanceled() event.

chrome/browser/extensions/extension_event_router.h

Index: chrome/browser/extensions/extension_event_router.h
diff --git a/chrome/browser/extensions/extension_event_router.h b/chrome/browser/extensions/extension_event_router.h
index 834d85f258453277ab1d21e5f8df52ca26279398..96011c4335cd1adebd161b1a0e466d19a68abd11 100644
--- a/chrome/browser/extensions/extension_event_router.h
+++ b/chrome/browser/extensions/extension_event_router.h
@@ -214,6 +214,9 @@ class ExtensionEventRouter : public content::NotificationObserver,
                               content::RenderProcessHost* process,
                               const linked_ptr<ExtensionEvent>& event);
 
+  // Prevents the given extension from being suspended.
+  void CancelSuspend(Profile* profile, const extensions::Extension* extension);
+
   // Returns false when the event is scoped to a profile and the listening
   // extension does not have access to events from that profile. Also fills
   // |event_args| with the proper arguments to send, which may differ if