Refactor code that defers extension background page loading

extensions/browser/process_manager.cc

Index: extensions/browser/process_manager.cc
diff --git a/extensions/browser/process_manager.cc b/extensions/browser/process_manager.cc
index f6297ec21c8f79c01e0a5d1c796a17043e8e0fd9..1017ff7166b1d2c239b0c4c1a0971c16bc7f4e32 100644
--- a/extensions/browser/process_manager.cc
+++ b/extensions/browser/process_manager.cc
@@ -227,6 +227,7 @@ ProcessManager::ProcessManager(BrowserContext* context,
         &ProcessManager::OnDevToolsStateChanged,
         base::Unretained(this))),
     weak_ptr_factory_(this) {
+  LOG(ERROR) << "JAMES new ProcessManager";
   registrar_.Add(this, chrome::NOTIFICATION_EXTENSIONS_READY,
                  content::Source<BrowserContext>(original_context));
   registrar_.Add(this,
@@ -615,13 +616,14 @@ void ProcessManager::CancelSuspend(const Extension* extension) {
 }
 
 void ProcessManager::OnBrowserWindowReady() {
+  LOG(ERROR) << "JAMES OnBrowserWindowReady";
   // If the extension system isn't ready yet the background hosts will be
   // created via NOTIFICATION_EXTENSIONS_READY below.
   ExtensionSystem* system = ExtensionSystem::Get(GetBrowserContext());
   if (!system->ready().is_signaled())
     return;
 
-  CreateBackgroundHostsForProfileStartup();
+  MaybeCreateBackgroundHostsForStartup();
 }
 
 content::BrowserContext* ProcessManager::GetBrowserContext() const {
@@ -644,13 +646,12 @@ void ProcessManager::Observe(int type,
   switch (type) {
     case chrome::NOTIFICATION_EXTENSIONS_READY:
     case chrome::NOTIFICATION_PROFILE_CREATED: {
-       // Don't load background hosts now if the loading should be deferred.
-       // Instead they will be loaded when a browser window for this profile
-       // (or an incognito profile from this profile) is ready.
-       if (DeferLoadingBackgroundHosts())
-         break;
+      if (type == chrome::NOTIFICATION_EXTENSIONS_READY)
+        LOG(ERROR) << "JAMES got extensions_ready";
+      else
+        LOG(ERROR) << "JAMES got profile_created";
 
-      CreateBackgroundHostsForProfileStartup();
+      MaybeCreateBackgroundHostsForStartup();
       break;
     }
 
@@ -742,6 +743,7 @@ void ProcessManager::Observe(int type,
     }
 
     case chrome::NOTIFICATION_PROFILE_DESTROYED: {
+      LOG(ERROR) << "JAMES got profile_destroyed";
       // Close background hosts when the last browser is closed so that they
       // have time to shutdown various objects on different threads. Our
       // destructor is called too late in the shutdown sequence.
@@ -778,12 +780,16 @@ void ProcessManager::OnDevToolsStateChanged(
   }
 }
 
-void ProcessManager::CreateBackgroundHostsForProfileStartup() {
-  if (startup_background_hosts_created_ ||
-      !ExtensionsBrowserClient::Get()->
-          IsBackgroundPageAllowed(GetBrowserContext())) {
+void ProcessManager::MaybeCreateBackgroundHostsForStartup() {
+  if (startup_background_hosts_created_)
+    return;
+
+  // The embedder might want to defer background page loading. For example,
+  // Chrome defers background page loading when it is launched to show the app
+  // list, then triggers a load later via OnBrowserWindowReady().
+  if (ExtensionsBrowserClient::Get()->DeferLoadingBackgroundHosts(
+          GetBrowserContext()))
     return;
-  }
 
   const ExtensionSet& enabled_extensions =
       ExtensionRegistry::Get(GetBrowserContext())->enabled_extensions();