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 f46e8880abe6bb7c7781cc32bf6ea2d4e1009b2a..f72319a0bcf6d41b886a2380c12183127c54bd30 100644
--- a/chrome/browser/extensions/extension_host.cc
+++ b/chrome/browser/extensions/extension_host.cc
@@ -22,6 +22,7 @@
 #include "chrome/browser/extensions/window_controller.h"
 #include "chrome/browser/file_select_helper.h"
 #include "chrome/browser/intents/web_intents_util.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"
@@ -137,6 +138,7 @@ ExtensionHost::ExtensionHost(const Extension* extension,
       render_view_host_(NULL),
       did_stop_loading_(false),
       document_element_available_(false),
+      keeping_browser_process_alive_(false),
       initial_url_(url),
       ALLOW_THIS_IN_INITIALIZER_LIST(
           extension_function_dispatcher_(profile_, this)),
@@ -169,6 +171,11 @@ ExtensionHost::~ExtensionHost() {
       content::Source<Profile>(profile_),
       content::Details<ExtensionHost>(this));
   ProcessCreationQueue::GetInstance()->Remove(this);
+
+#if !defined(OS_ANDROID)
+  if (keeping_browser_process_alive_)
+    browser::EndKeepAlive();
+#endif
 }
 
 void ExtensionHost::CreateView(Browser* browser) {
@@ -460,6 +467,16 @@ void ExtensionHost::DidCloseJavaScriptDialog() {
     pm->DecrementLazyKeepaliveCount(extension());
 }
 
+void ExtensionHost::SetKeepsBrowserProcessAlive() {
+  if (keeping_browser_process_alive_)
+    return;
+
+#if !defined(OS_ANDROID)
+  keeping_browser_process_alive_ = true;
+  browser::StartKeepAlive();
+#endif
+}
+
 WebContents* ExtensionHost::OpenURLFromTab(WebContents* source,
                                            const OpenURLParams& params) {
   // Whitelist the dispositions we will allow to be opened.