Fix bug where transient pages would miss events dispatched while it was

chrome/browser/extensions/extension_event_router.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/extensions/extension_event_router.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/values.h"
 #include "chrome/browser/extensions/api/runtime/runtime_api.h"
@@ skipping 387 matching lines @@
   if (queue->ShouldEnqueueTask(profile, extension)) {
     queue->AddPendingTask(
         profile, extension->id(),
         base::Bind(&ExtensionEventRouter::DispatchPendingEvent,
                    base::Unretained(this), event));
   }
 }
 
 void ExtensionEventRouter::IncrementInFlightEvents(
     Profile* profile, const Extension* extension) {
+  // Only increment in-flight events if the lazy background page is active,
+  // because that's the only time we'll get an ACK.
   if (extension->has_lazy_background_page()) {
-    profile->GetExtensionProcessManager()->IncrementLazyKeepaliveCount(
-        extension);
+    ExtensionProcessManager* pm =
+        ExtensionSystem::Get(profile)->process_manager();
+    ExtensionHost* host = pm->GetBackgroundHostForExtension(extension->id());
+    if (host)
+      pm->IncrementLazyKeepaliveCount(extension);
   }
 }
 
-void ExtensionEventRouter::OnExtensionEventAck(
+void ExtensionEventRouter::OnEventAck(
     Profile* profile, const std::string& extension_id) {
-  const Extension* extension = profile->GetExtensionService()->extensions()->
-      GetByID(extension_id);
-  if (extension && extension->has_lazy_background_page()) {
-    profile->GetExtensionProcessManager()->DecrementLazyKeepaliveCount(
-        extension);
-  }
+  ExtensionProcessManager* pm =
+      ExtensionSystem::Get(profile)->process_manager();
+  ExtensionHost* host = pm->GetBackgroundHostForExtension(extension_id);
+  // The event ACK is routed to the background host, so this should never be
+  // NULL.
+  CHECK(host);
+  CHECK(host->extension()->has_lazy_background_page());
+  pm->DecrementLazyKeepaliveCount(host->extension());
 }
 
 void ExtensionEventRouter::DispatchPendingEvent(
     const linked_ptr<ExtensionEvent>& event, ExtensionHost* host) {
   if (!host)
     return;
 
   ListenerProcess listener(host->render_process_host(),
                            host->extension()->id());
   if (listeners_[event->event_name].count(listener) > 0u)
@@ skipping 57 matching lines @@
           content::Details<const Extension>(details).ptr();
       extensions::RuntimeEventRouter::DispatchOnInstalledEvent(
           profile_, extension);
       break;
     }
     default:
       NOTREACHED();
       return;
   }
 }