Fix a bug where calling window.close() from a transient page with an open

message port would result in an inconsistent lazy keepalive count.

BUG=no
TEST=no

Review URL: https://chromiumcodereview.appspot.com/9961020

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@131000 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 14 insertions, 9 deletions

diff --git a/chrome/browser/extensions/extension_event_router.cc b/chrome/browser/extensions/extension_event_router.cc
index 32206f4..21c315c 100644
--- a/chrome/browser/extensions/extension_event_router.cc
+++ b/chrome/browser/extensions/extension_event_router.cc
@@ -414,16 +414,11 @@ void ExtensionEventRouter::IncrementInFlightEvents(
 
 void ExtensionEventRouter::OnExtensionEventAck(
     Profile* profile, const std::string& extension_id) {
-  // Don't decrement the count if the background page has gone away. This can
-  // happen if the event was dispatched while unloading the page.
-  // TODO(mpcomplete): This might be insufficient.. what if the page goes away
-  // and comes back before we get the ack? Then we'll have an imbalanced
-  // keepalive count.
-  ExtensionHost* host = profile->GetExtensionProcessManager()->
-      GetBackgroundHostForExtension(extension_id);
-  if (host && host->extension()->has_lazy_background_page()) {
+  const Extension* extension = profile->GetExtensionService()->extensions()->
+      GetByID(extension_id);
+  if (extension && extension->has_lazy_background_page()) {
     profile->GetExtensionProcessManager()->DecrementLazyKeepaliveCount(
-        host->extension());
+        extension);
   }
 }
 
diff --git a/chrome/browser/extensions/extension_process_manager.cc b/chrome/browser/extensions/extension_process_manager.cc
index 782f642..30fcb4d 100644
--- a/chrome/browser/extensions/extension_process_manager.cc
+++ b/chrome/browser/extensions/extension_process_manager.cc
@@ -397,6 +397,16 @@ int ExtensionProcessManager::DecrementLazyKeepaliveCount(
   if (!extension->has_lazy_background_page())
     return 0;
 
+  // Don't decrement the count if the background page has gone away. This can
+  // happen e.g. if an event was dispatched while unloading the page, or if
+  // the process is killed/closed while a message port remains open.
+  // TODO(mpcomplete): This might be insufficient.. what if the page goes away
+  // and comes back before we get here? Then we'll have an imbalanced
+  // keepalive count.
+  ExtensionHost* host = GetBackgroundHostForExtension(extension->id());
+  if (!host)
+    return 0;
+
   int& count = background_page_data_[extension->id()].lazy_keepalive_count;
   DCHECK_GT(count, 0);
   if (--count == 0)