Identity API: defer loading component app

chrome/browser/extensions/api/identity/web_auth_flow.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/extensions/api/identity/web_auth_flow.h"
 
 #include "base/location.h"
 #include "base/message_loop.h"
 #include "base/utf_string_conversions.h"
+#include "chrome/browser/extensions/component_loader.h"
+#include "chrome/browser/extensions/extension_service.h"
+#include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_navigator.h"
 #include "content/public/browser/load_notification_details.h"
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/notification_details.h"
 #include "content/public/browser/notification_source.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/resource_request_details.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/page_transition_types.h"
 #include "googleurl/src/gurl.h"
+#include "grit/browser_resources.h"
 #include "ui/base/window_open_disposition.h"
 
 using content::LoadNotificationDetails;
 using content::NavigationController;
 using content::RenderViewHost;
 using content::ResourceRedirectDetails;
 using content::WebContents;
 using content::WebContentsObserver;
 
 namespace extensions {
@@ skipping 26 matching lines @@
   if (contents_) {
     // The popup owns the contents if it was displayed.
     if (popup_shown_)
       contents_->Close();
     else
       delete contents_;
   }
 }
 
 void WebAuthFlow::Start() {
+  static bool is_component_loaded = false;

[Matt Perry, 2013/05/29 00:39:28]

This isn't multi-profile safe.

[Michael Courage, 2013/05/29 00:49:37]

Good point. Is it reasonable/cheap to just do this unconditionally? It looked to
me like a lot of stuff was happening behind that Add call, so I threw in this
conditional. Seems like I should use a profile keyed service unless there is
some simpler way.

[Matt Perry, 2013/05/29 00:53:38]

This will actually cause the app to reload, which it's probably best to avoid.
Can you use ComponentLoader::Exists? You need the app ID, but that should be
known.

[Michael Courage, 2013/05/29 01:49:53]

ComponentLoader::Exists will do the trick, thanks.

It occurs to me that I really ought to put this code in
https://codereview.chromium.org/15897006/, which is where WebAuthFlow will
actually make use of the component app. I'll do that and just keep this CL
focused on fixing the memory issue.

+  if (!is_component_loaded) {
+    extensions::ExtensionSystem* extension_system =
+        extensions::ExtensionSystem::Get(profile_);
+    ExtensionService* extension_service = extension_system->extension_service();
+    extension_service->component_loader()->Add(
+        IDR_IDENTITY_API_SCOPE_APPROVAL_MANIFEST,
+        base::FilePath(FILE_PATH_LITERAL("identity_scope_approval_dialog")));
+    is_component_loaded = true;
+  }
+
   contents_ = CreateWebContents();
   WebContentsObserver::Observe(contents_);
 
   NavigationController* controller = &(contents_->GetController());
 
   // Register for appropriate notifications to intercept navigation to the
   // redirect URLs.
   registrar_.Add(
       this,
       content::NOTIFICATION_RESOURCE_RECEIVED_REDIRECT,
@@ skipping 92 matching lines @@
   AfterUrlLoaded();
 }
 
 void WebAuthFlow::WebContentsDestroyed(WebContents* web_contents) {
   contents_ = NULL;
   if (delegate_)
     delegate_->OnAuthFlowFailure(WebAuthFlow::WINDOW_CLOSED);
 }
 
 }  // namespace extensions