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..eaa4a6e1a716597a4a6d8a716ec33963de6e59af 100644
--- a/chrome/browser/extensions/extension_event_router.h
+++ b/chrome/browser/extensions/extension_event_router.h
@@ -214,6 +214,18 @@ class ExtensionEventRouter : public content::NotificationObserver,
                               content::RenderProcessHost* process,
                               const linked_ptr<ExtensionEvent>& event);
 
+  // Dispatch "onSuspendCanceled" to a particular extension.
+  void DispatchOnSuspendCanceled(
+      content::RenderProcessHost* process, const std::string& extension_id);
+
+  // Returns true if the given extension is in the process of unloading. More
+  // specifically, this will return true in the phase where the onSuspend event
+  // has been fired, but before the extension's background page has been
+  // unloaded. During this period other events that arrive for the extension
+  // cause the unload process to be canceled and an onSuspendCanceled event to
+  // be sent.
+  bool IsClosing(Profile* profile, const extensions::Extension* extension);

[benwells, 2012/07/19 04:01:21]

Could we rename this to MightBeClosing, MaybeClosing, FlaggedToClose... or
something to indicate it might not be closed?

[koz (OOO until 15th September), 2012/07/19 06:52:11]

Hm, I don't think IsClosing() is such a bad name. The fact that it's
IsClosing(), not IsClosed() implies that it is in the process of closing, and
that it's cancelable is not something we need to document in the name of the
function.

In other words, closing is the five second process, not the thing that happens
instantaneously after a delay.

+
   // 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