[Chromecast] Launch background pages while loading an extension

We need a ProcessManager to exist in order to load background
pages but like everything extension-related it is lazy created

Bug: b/73768170
Test: load extension at start verify background script prints occur


Change-Id: I63ccc58ee819ec0435646c296ceb0d7678c433cc
Reviewed-on: https://chromium-review.googlesource.com/959343Reviewed-by: Kevin Schoedel <kpschoedel@chromium.org>
Reviewed-by: Luke Halliwell <halliwell@chromium.org>
Commit-Queue: Albert Chaulk <achaulk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#545851}

chromecast/browser/cast_browser_main_parts.cc

@@ -100,6 +100,7 @@
 #include "chromecast/browser/extensions/cast_prefs.h"
 #include "chromecast/common/cast_extensions_client.h"
 #include "components/keyed_service/content/browser_context_dependency_manager.h"  // nogncheck
+#include "extensions/browser/browser_context_keyed_service_factories.h"  // nogncheck
 #include "extensions/browser/extension_prefs.h"  // nogncheck
 #endif
 
@@ -541,6 +542,8 @@ void CastBrowserMainParts::PreMainMessageLoopRun() {
           cast_browser_process_->browser_context(), user_pref_service_.get());
   extensions::ExtensionsBrowserClient::Set(extensions_browser_client_.get());
 
+  extensions::EnsureBrowserContextKeyedServiceFactoriesBuilt();
+
   extensions::CastExtensionSystem* extension_system =
       static_cast<extensions::CastExtensionSystem*>(
           extensions::ExtensionSystem::Get(

chromecast/browser/extensions/cast_extension_system.cc

@@ -20,8 +20,10 @@
 #include "extensions/browser/extension_prefs.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/browser/info_map.h"
+#include "extensions/browser/lazy_background_task_queue.h"
 #include "extensions/browser/notification_types.h"
 #include "extensions/browser/null_app_sorting.h"
+#include "extensions/browser/process_manager.h"
 #include "extensions/browser/quota_service.h"
 #include "extensions/browser/renderer_startup_helper.h"
 #include "extensions/browser/runtime_data.h"
@@ -32,6 +34,7 @@
 #include "extensions/common/constants.h"
 #include "extensions/common/file_util.h"
 #include "extensions/common/manifest_constants.h"
+#include "extensions/common/manifest_handlers/background_info.h"
 
 using content::BrowserContext;
 using content::BrowserThread;
@@ -95,7 +98,7 @@ const Extension* CastExtensionSystem::LoadExtensionByManifest(
     return nullptr;
   }
 
-  extension_registrar_->AddExtension(extension);
+  PostLoadExtension(extension);
 
   return extension.get();
 }
@@ -124,16 +127,23 @@ const Extension* CastExtensionSystem::LoadExtension(
       LOG(WARNING) << warning.message;
   }
 
-  extension_registrar_->AddExtension(extension);
+  PostLoadExtension(extension);
 
   return extension.get();
 }
 
+void CastExtensionSystem::PostLoadExtension(
+    const scoped_refptr<extensions::Extension>& extension) {
+  extension_registrar_->AddExtension(extension);
+}
+
 const Extension* CastExtensionSystem::LoadApp(const base::FilePath& app_dir) {
   return LoadExtension(app_dir);
 }
 
 void CastExtensionSystem::Init() {
+  extensions::ProcessManager::Get(browser_context_);
+
   // Inform the rest of the extensions system to start.
   ready_.Signal();
   content::NotificationService::current()->Notify(

chromecast/browser/extensions/cast_extension_system.h

@@ -102,6 +102,7 @@ class CastExtensionSystem : public ExtensionSystem,
   bool ShouldBlockExtension(const Extension* extension) override;
 
  private:
+  void PostLoadExtension(const scoped_refptr<extensions::Extension>& extension);
   void OnExtensionRegisteredWithRequestContexts(
       scoped_refptr<Extension> extension);
   content::BrowserContext* browser_context_;  // Not owned.