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

chrome/browser/extensions/platform_app_launcher.cc

Index: chrome/browser/extensions/platform_app_launcher.cc
diff --git a/chrome/browser/extensions/platform_app_launcher.cc b/chrome/browser/extensions/platform_app_launcher.cc
index b1276416e0de85f9c419dc56b17f6cd7c1ee809b..6da068d120d915e70f01b0dc11de058499bc4c8f 100644
--- a/chrome/browser/extensions/platform_app_launcher.cc
+++ b/chrome/browser/extensions/platform_app_launcher.cc
@@ -16,6 +16,7 @@
 #include "chrome/browser/extensions/extension_process_manager.h"
 #include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/extensions/lazy_background_task_queue.h"
+#include "chrome/browser/extensions/platform_app_service.h"
 #include "chrome/browser/intents/web_intents_util.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/extensions/extension.h"
@@ -346,6 +347,7 @@ void LaunchPlatformApp(Profile* profile,
                        const Extension* extension,
                        const CommandLine* command_line,
                        const FilePath& current_directory) {
+  PlatformAppService::CreateInstance(profile);
   FilePath path;
   if (!GetAbsolutePathFromCommandLine(command_line, current_directory, &path)) {
     LaunchPlatformAppWithNoData(profile, extension);
@@ -358,6 +360,7 @@ void LaunchPlatformApp(Profile* profile,
 void LaunchPlatformAppWithPath(Profile* profile,
                                const Extension* extension,
                                const FilePath& file_path) {
+  PlatformAppService::CreateInstance(profile);
   // launcher will be freed when nothing has a reference to it. The message
   // queue will retain a reference for any outstanding task, so when the
   // launcher has finished it will be freed.
@@ -371,6 +374,7 @@ void LaunchPlatformAppWithWebIntent(
     const Extension* extension,
     content::WebIntentsDispatcher* intents_dispatcher,
     content::WebContents* source) {
+  PlatformAppService::CreateInstance(profile);
   scoped_refptr<PlatformAppWebIntentLauncher> launcher =
       new PlatformAppWebIntentLauncher(
           profile, extension, intents_dispatcher, source);