Keep browser process alive while there are platform apps with background pages running.

chrome/browser/extensions/extension_host.cc

Index: chrome/browser/extensions/extension_host.cc
diff --git a/chrome/browser/extensions/extension_host.cc b/chrome/browser/extensions/extension_host.cc
index d370c268c555b51ae652538ac323cac0c26de36b..76ef390241c620232ecce971c78a3cd66a546794 100644
--- a/chrome/browser/extensions/extension_host.cc
+++ b/chrome/browser/extensions/extension_host.cc
@@ -21,6 +21,7 @@
 #include "chrome/browser/extensions/extension_tab_util.h"
 #include "chrome/browser/extensions/window_controller.h"
 #include "chrome/browser/file_select_helper.h"
+#include "chrome/browser/lifetime/application_lifetime.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/app_modal_dialogs/javascript_dialog_creator.h"
 #include "chrome/browser/ui/browser.h"
@@ -154,6 +155,13 @@ ExtensionHost::ExtensionHost(const Extension* extension,
   // be the same extension that this points to.
   registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_UNLOADED,
                  content::Source<Profile>(profile_));
+
+  // Keep the browser process alive while platform apps have active background
+  // pages.
+  if (extension_->is_platform_app() &&
+      extension_host_type_ == chrome::VIEW_TYPE_EXTENSION_BACKGROUND_PAGE) {

[benwells, 2012/10/12 05:33:38]

I don't like putting the is_platform_app check here. This is the only difference
so far for platform apps in the background page behavior.

Also, the extension_host_type check is strictly unnecessary but it feels less
fragile / scary with it in.

[Aaron Boodman, 2012/10/12 17:58:30]

What about if ExtensionHost supported this feature as a property:

extension_host->set_keeps_browser_alive(true)

Would there be a natural app-specific place to call this?

+    browser::StartKeepAlive();
+  }
 }
 
 ExtensionHost::~ExtensionHost() {
@@ -167,6 +175,11 @@ ExtensionHost::~ExtensionHost() {
       content::Source<Profile>(profile_),
       content::Details<ExtensionHost>(this));
   ProcessCreationQueue::GetInstance()->Remove(this);
+
+  if (extension_->is_platform_app() &&
+      extension_host_type_ == chrome::VIEW_TYPE_EXTENSION_BACKGROUND_PAGE) {
+    browser::EndKeepAlive();
+  }
 }
 
 void ExtensionHost::CreateView(Browser* browser) {