Fix imbalanced keepalive count for event pages when dealing with other views.

chrome/browser/extensions/extension_process_manager.cc

Index: chrome/browser/extensions/extension_process_manager.cc
diff --git a/chrome/browser/extensions/extension_process_manager.cc b/chrome/browser/extensions/extension_process_manager.cc
index cf7230f675a9beef6f439f1a6f62540e7ccab633..f8a72ab5e8b4c01c1bb5d71006d601dd0df7521a 100644
--- a/chrome/browser/extensions/extension_process_manager.cc
+++ b/chrome/browser/extensions/extension_process_manager.cc
@@ -345,8 +345,7 @@ const Extension* ExtensionProcessManager::GetExtensionForRenderViewHost(
 
   ExtensionService* service =
       ExtensionSystem::Get(GetProfile())->extension_service();
-  return service->extensions()->GetByID(
-      render_view_host->GetSiteInstance()->GetSite().host());
+  return service->extensions()->GetByID(GetExtensionID(render_view_host));
 }
 
 void ExtensionProcessManager::RegisterRenderViewHost(
@@ -554,7 +553,7 @@ void ExtensionProcessManager::Observe(
     case chrome::NOTIFICATION_EXTENSION_HOST_DESTROYED: {
       ExtensionHost* host = content::Details<ExtensionHost>(details).ptr();
       if (background_hosts_.erase(host))
-        background_page_data_.erase(host->extension()->id());
+        ClearBackgroundPageData(host->extension()->id());
       platform_app_hosts_.erase(host);
       break;
     }
@@ -646,6 +645,20 @@ void ExtensionProcessManager::CloseBackgroundHosts() {
   }
 }
 
+void ExtensionProcessManager::ClearBackgroundPageData(
+    const std::string& extension_id) {
+  background_page_data_.erase(extension_id);
+
+  // Re-register all RenderViews for this extension. We do this to restore

[Yoyo Zhou, 2012/05/03 00:10:25]

Do we need to do this, or could we just not erase the background_page_data_ for
this extension if it had views open?

[Matt Perry, 2012/05/03 00:18:38]

I think we still need to erase background_page_data. The reason it's erased is
that some of the Decrement signals come from the background page itself. When
the page unloads, it doesn't always get a chance to send the Decrement messages
(or they are ignored when the ExtensionHost is gone), so we reset it to 0 here.

+  // the lazy_keepalive_count (if any) to properly reflect the number of open
+  // views.
+  for (ExtensionRenderViews::const_iterator it = all_extension_views_.begin();
+       it != all_extension_views_.end(); ++it) {
+    if (GetExtensionID(it->first) == extension_id)
+      UpdateRegisteredRenderView(it->first);
+  }
+}
+
 //
 // IncognitoExtensionProcessManager
 //