Initialize OOBE/login WebUI in hidden state in parallel with wallpaper animation.

chrome/browser/chromeos/login/webui_login_display_host.cc

Index: chrome/browser/chromeos/login/webui_login_display_host.cc
diff --git a/chrome/browser/chromeos/login/webui_login_display_host.cc b/chrome/browser/chromeos/login/webui_login_display_host.cc
index 8cb20bd4accf8454a572611224b5009debbe2856..f244ac1b5f7ee202eb3f3d1ad1487a1953cade75 100644
--- a/chrome/browser/chromeos/login/webui_login_display_host.cc
+++ b/chrome/browser/chromeos/login/webui_login_display_host.cc
@@ -23,6 +23,7 @@
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/chrome_switches.h"
 #include "content/public/browser/notification_service.h"
+#include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_ui.h"
 #include "ui/aura/env.h"
 #include "ui/aura/window.h"
@@ -43,6 +44,15 @@ const int kLoginFadeoutTransitionDurationMs = 700;
 // Number of times we try to reload OOBE/login WebUI if it crashes.
 const int kCrashCountLimit = 5;
 
+// When wallpaper animation is not disabled (no flag --disable-boot-animation)
+// initialize OOBE/sign in WebUI in hidden state in parallel with
+// wallpaper animation.
+const bool kInitializeWebUIInParallelDefault = true;
+
+// Switch values that might be used to override WebUI init type.
+const char kWebUIInitParallel[] = "parallel";
+const char kWebUIInitPostpone[] = "postpone";
+
 }  // namespace
 
 // WebUILoginDisplayHost -------------------------------------------------------
@@ -54,6 +64,8 @@ WebUILoginDisplayHost::WebUILoginDisplayHost(const gfx::Rect& background_bounds)
       webui_login_display_(NULL),
       is_showing_login_(false),
       is_wallpaper_loaded_(false),
+      initialize_webui_in_parallel_(kInitializeWebUIInParallelDefault),
+      status_area_saved_visibility_(false),
       crash_count_(0),
       restore_path_(RESTORE_UNKNOWN) {
   bool is_registered = WizardController::IsDeviceRegistered();
@@ -74,7 +86,19 @@ WebUILoginDisplayHost::WebUILoginDisplayHost(const gfx::Rect& background_bounds)
                    content::NotificationService::AllSources());
     // Prevents white flashing on OOBE (http://crbug.com/131569).
     aura::Env::GetInstance()->set_render_white_bg(false);
+
+    // Check if WebUI init type is overriden.
+    if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kAshWebUIInit)) {
+      const std::string override_type = CommandLine::ForCurrentProcess()->
+          GetSwitchValueASCII(switches::kAshWebUIInit);
+      if (override_type == kWebUIInitParallel)
+        initialize_webui_in_parallel_ = true;
+      else if (override_type == kWebUIInitPostpone)
+        initialize_webui_in_parallel_ = false;
+    }
   }
+  // In case if we're not waiting for wallpaper load,
+  // |initialize_webui_in_parallel_| value is ignored through the code flow.
 }
 
 WebUILoginDisplayHost::~WebUILoginDisplayHost() {
@@ -112,7 +136,9 @@ void WebUILoginDisplayHost::SetShutdownButtonEnabled(bool enable) {
 }
 
 void WebUILoginDisplayHost::SetStatusAreaVisible(bool visible) {
-  if (login_view_)
+  if (waiting_for_wallpaper_load_  && initialize_webui_in_parallel_)
+    status_area_saved_visibility_ = visible;
+  else if (login_view_)
     login_view_->SetStatusAreaVisible(visible);
 }
 
@@ -128,7 +154,7 @@ void WebUILoginDisplayHost::StartWizard(const std::string& first_screen_name,
   is_showing_login_ = false;
   scoped_ptr<DictionaryValue> scoped_parameters(screen_parameters);
 
-  if (waiting_for_wallpaper_load_)
+  if (waiting_for_wallpaper_load_ && !initialize_webui_in_parallel_)
     return;
 
   if (!login_window_)
@@ -142,7 +168,7 @@ void WebUILoginDisplayHost::StartSignInScreen() {
   restore_path_ = RESTORE_SIGN_IN;
   is_showing_login_ = true;
 
-  if (waiting_for_wallpaper_load_)
+  if (waiting_for_wallpaper_load_ && !initialize_webui_in_parallel_)
     return;
 
   if (!login_window_)
@@ -178,8 +204,12 @@ void WebUILoginDisplayHost::Observe(
     is_wallpaper_loaded_ = true;
     ash::Shell::GetInstance()->user_wallpaper_delegate()->
         OnWallpaperBootAnimationFinished();
-    if (waiting_for_wallpaper_load_)
-      StartPostponedWebUI();
+    if (waiting_for_wallpaper_load_) {
+      if (initialize_webui_in_parallel_)
+        ShowWebUI();
+      else
+        StartPostponedWebUI();
+    }
     registrar_.Remove(this,
                       chrome::NOTIFICATION_WALLPAPER_ANIMATION_FINISHED,
                       content::NotificationService::AllSources());
@@ -215,7 +245,16 @@ void WebUILoginDisplayHost::LoadURL(const GURL& url) {
     login_window_->SetContentsView(login_view_);
     login_view_->UpdateWindowType();
 
-    login_window_->Show();
+    // When not waiting for wallpaper any request to load a URL in WebUI
+    // should trigger window visibility as well.
+    // Otherwise, when we're waiting for wallpaper load then show WebUI
+    // right away only if it is not initialized in parallel i.e. was postponed.
+    // In case of WebUI being initialized in parallel with wallpaper load
+    // it will be hidden initially.
+    if (!waiting_for_wallpaper_load_ || !initialize_webui_in_parallel_)
+      login_window_->Show();
+    else
+      login_view_->set_is_hidden(true);
     login_window_->GetNativeView()->SetName("WebUILoginView");
     login_view_->OnWindowCreated();
   }
@@ -263,6 +302,17 @@ WizardController* WebUILoginDisplayHost::CreateWizardController() {
   return new WizardController(this, oobe_display);
 }
 
+void WebUILoginDisplayHost::ShowWebUI() {
+  if (!login_window_ || !login_view_) {
+    NOTREACHED();
+    return;
+  }
+  login_window_->Show();
+  login_view_->GetWebContents()->Focus();
+  login_view_->SetStatusAreaVisible(status_area_saved_visibility_);
+  login_view_->OnPostponedShow();
+}
+
 void WebUILoginDisplayHost::StartPostponedWebUI() {
   if (!waiting_for_wallpaper_load_ || !is_wallpaper_loaded_) {
     NOTREACHED();