cros: Smoothen the transition between boot splash and full-screen OOBE

1) The full-screen white background in OOBE is rendered in web-ui, so
   there's a delay showing it. Users will see a glimpse of the default
   wallpaper (it's blue on an eve) between the boot splash screen
   and the OOBE screen (both white). To avoid this, we can show a white
   wallpaper during the entire OOBE screen, which can show right after
   the boot splash seamlessly.

2) The original idea was to delay the dismissal of the boot splash
   screen until OOBE dialog is ready. However, boot splash screen will
   not always show (e.g. when a guest user exits, or browser crash and
   restart). In such cases, we also want to avoid showing the blue
   default wallpaper before the white OOBE screen is loaded. Therefore,
   showing a white wallpaper is a better solution.

Bug: 872936
Change-Id: Iaa600f9d455956743a6cfd3dd26f07ad2a4ed61d
Reviewed-on: https://chromium-review.googlesource.com/1172066Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Oliver Chang <ochang@chromium.org>
Reviewed-by: Xiaoqian Dai <xdai@chromium.org>
Commit-Queue: Wenzhao (Colin) Zang <wzang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#583154}

ash/public/cpp/wallpaper_types.h

@@ -57,7 +57,12 @@ enum WallpaperType {
   DEVICE = 7,        // Current wallpaper is the device policy controlled
                      // wallpaper. It shows on the login screen if the device
                      // is an enterprise managed device.
-  WALLPAPER_TYPE_COUNT = 8
+  ONE_SHOT = 8,      // Current wallpaper is shown one-time only, which doesn't
+                     // belong to a particular user and isn't saved to file. It
+                     // goes away when another wallpaper is shown or the browser
+                     // process exits. Note: the image will never be blurred or
+                     // dimmed.
+  WALLPAPER_TYPE_COUNT = 9
 };
 
 // The color profile type, ordered as the color profiles applied in

ash/public/interfaces/wallpaper.mojom

@@ -199,6 +199,12 @@ interface WallpaperController {
   // device policy wallpaper or the default wallpaper.
   ShowSigninWallpaper();
 
+  // Shows a one-shot wallpaper, which does not belong to any particular user
+  // and is not saved to file. Note: the wallpaper will never be dimmed or
+  // blurred because it's assumed that the caller wants to show the image as is
+  // when using this method.
+  ShowOneShotWallpaper(gfx.mojom.ImageSkia image);
+
   // Removes all of the user's saved wallpapers and related info.
   // |wallpaper_files_id|: The file id for user_info.account_id.
   RemoveUserWallpaper(WallpaperUserInfo user_info, string wallpaper_files_id);

ash/wallpaper/wallpaper_controller.cc

@@ -234,11 +234,11 @@ bool ResizeAndSaveWallpaper(const gfx::ImageSkia& image,
   return written_bytes == data->size();
 }
 
-// Creates a 1x1 solid color image to be used as the backup default wallpaper.
-gfx::ImageSkia CreateSolidColorWallpaper() {
+// Creates a 1x1 solid color image.
+gfx::ImageSkia CreateSolidColorWallpaper(SkColor color) {
   SkBitmap bitmap;
   bitmap.allocN32Pixels(1, 1);
-  bitmap.eraseColor(kDefaultWallpaperColor);
+  bitmap.eraseColor(color);
   return gfx::ImageSkia::CreateFrom1xBitmap(bitmap);
 }
 
@@ -728,12 +728,13 @@ void WallpaperController::UpdateWallpaperBlur(bool blur) {
 
 bool WallpaperController::ShouldApplyDimming() const {
   return Shell::Get()->session_controller()->IsUserSessionBlocked() &&
+         !IsOneShotWallpaper() &&
          !base::CommandLine::ForCurrentProcess()->HasSwitch(
              switches::kAshDisableLoginDimAndBlur);
 }
 
 bool WallpaperController::IsBlurAllowed() const {
-  return !IsDevicePolicyWallpaper() &&
+  return !IsDevicePolicyWallpaper() && !IsOneShotWallpaper() &&
          !base::CommandLine::ForCurrentProcess()->HasSwitch(
              switches::kAshDisableLoginDimAndBlur);
 }
@@ -955,7 +956,8 @@ void WallpaperController::SetOnlineWallpaperFromData(
                      weak_factory_.GetWeakPtr(), params, /*save_file=*/true,
                      std::move(callback));
   if (bypass_decode_for_testing_) {
-    std::move(decoded_callback).Run(CreateSolidColorWallpaper());
+    std::move(decoded_callback)
+        .Run(CreateSolidColorWallpaper(kDefaultWallpaperColor));
     return;
   }
   // Use default codec because 1) online wallpapers may have various formats,
@@ -1020,7 +1022,7 @@ void WallpaperController::SetPolicyWallpaper(
       POLICY, WALLPAPER_LAYOUT_CENTER_CROPPED, show_wallpaper);
 
   if (bypass_decode_for_testing_) {
-    std::move(callback).Run(CreateSolidColorWallpaper());
+    std::move(callback).Run(CreateSolidColorWallpaper(kDefaultWallpaperColor));
     return;
   }
   // The default codec cannot be used here because the image data is provided by
@@ -1211,6 +1213,13 @@ void WallpaperController::ShowSigninWallpaper() {
   }
 }
 
+void WallpaperController::ShowOneShotWallpaper(const gfx::ImageSkia& image) {
+  const WallpaperInfo info = {
+      std::string(), WallpaperLayout::WALLPAPER_LAYOUT_STRETCH,
+      WallpaperType::ONE_SHOT, base::Time::Now().LocalMidnight()};
+  ShowWallpaperImage(image, info, /*preview_mode=*/false);
+}
+
 void WallpaperController::RemoveUserWallpaper(
     mojom::WallpaperUserInfoPtr user_info,
     const std::string& wallpaper_files_id) {
@@ -1625,7 +1634,7 @@ void WallpaperController::ReadAndDecodeWallpaper(
     const base::FilePath& file_path) {
   decode_requests_for_testing_.push_back(file_path);
   if (bypass_decode_for_testing_) {
-    std::move(callback).Run(CreateSolidColorWallpaper());
+    std::move(callback).Run(CreateSolidColorWallpaper(kDefaultWallpaperColor));
     return;
   }
   std::string* data = new std::string;
@@ -1783,7 +1792,8 @@ void WallpaperController::OnDefaultWallpaperDecoded(
     const gfx::ImageSkia& image) {
   if (image.isNull()) {
     // Create a solid color wallpaper if the default wallpaper decoding fails.
-    cached_default_wallpaper_.image = CreateSolidColorWallpaper();
+    cached_default_wallpaper_.image =
+        CreateSolidColorWallpaper(kDefaultWallpaperColor);
     cached_default_wallpaper_.file_path.clear();
   } else {
     cached_default_wallpaper_.image = image;
@@ -2006,6 +2016,11 @@ bool WallpaperController::IsDevicePolicyWallpaper() const {
          current_wallpaper_->wallpaper_info().type == WallpaperType::DEVICE;
 }
 
+bool WallpaperController::IsOneShotWallpaper() const {
+  return current_wallpaper_ &&
+         current_wallpaper_->wallpaper_info().type == WallpaperType::ONE_SHOT;
+}
+
 bool WallpaperController::ShouldSetDevicePolicyWallpaper() const {
   // Only allow the device wallpaper if the policy is in effect for enterprise
   // managed devices.

ash/wallpaper/wallpaper_controller.h

@@ -254,6 +254,7 @@ class ASH_EXPORT WallpaperController : public mojom::WallpaperController,
                                    WallpaperLayout layout) override;
   void ShowUserWallpaper(mojom::WallpaperUserInfoPtr user_info) override;
   void ShowSigninWallpaper() override;
+  void ShowOneShotWallpaper(const gfx::ImageSkia& image) override;
   void RemoveUserWallpaper(mojom::WallpaperUserInfoPtr user_info,
                            const std::string& wallpaper_files_id) override;
   void RemovePolicyWallpaper(mojom::WallpaperUserInfoPtr user_info,
@@ -503,6 +504,9 @@ class ASH_EXPORT WallpaperController : public mojom::WallpaperController,
   // Returns whether the current wallpaper is set by device policy.
   bool IsDevicePolicyWallpaper() const;
 
+  // Returns whether the current wallpaper has type of ONE_SHOT.
+  bool IsOneShotWallpaper() const;
+
   // Returns true if device wallpaper policy is in effect and we are at the
   // login screen right now.
   bool ShouldSetDevicePolicyWallpaper() const;

ash/wallpaper/wallpaper_controller_unittest.cc

@@ -2312,6 +2312,53 @@ TEST_F(WallpaperControllerTest, AddFirstWallpaperAnimationEndCallback) {
   EXPECT_TRUE(is_third_callback_run);
 }
 
+TEST_F(WallpaperControllerTest, ShowOneShotWallpaper) {
+  gfx::ImageSkia custom_wallpaper = CreateImage(640, 480, kWallpaperColor);
+  WallpaperLayout layout = WALLPAPER_LAYOUT_CENTER;
+  SimulateUserLogin(kUser1);
+  // First, set a custom wallpaper for |kUser1|. Verify the wallpaper is shown
+  // successfully and the user wallpaper info is updated.
+  controller_->SetCustomWallpaper(InitializeUser(account_id_1),
+                                  wallpaper_files_id_1, file_name_1, layout,
+                                  custom_wallpaper, false /*preview_mode=*/);
+  RunAllTasksUntilIdle();
+  EXPECT_EQ(1, GetWallpaperCount());
+  EXPECT_EQ(kWallpaperColor, GetWallpaperColor());
+  EXPECT_EQ(WallpaperType::CUSTOMIZED, controller_->GetWallpaperType());
+  const WallpaperInfo expected_wallpaper_info(
+      base::FilePath(wallpaper_files_id_1).Append(file_name_1).value(), layout,
+      WallpaperType::CUSTOMIZED, base::Time::Now().LocalMidnight());
+  WallpaperInfo wallpaper_info;
+  EXPECT_TRUE(controller_->GetUserWallpaperInfo(account_id_1, &wallpaper_info,
+                                                false /*is_ephemeral=*/));
+  EXPECT_EQ(expected_wallpaper_info, wallpaper_info);
+
+  // Show a one-shot wallpaper. Verify it is shown successfully.
+  ClearWallpaperCount();
+  constexpr SkColor kOneShotWallpaperColor = SK_ColorWHITE;
+  gfx::ImageSkia one_shot_wallpaper =
+      CreateImage(640, 480, kOneShotWallpaperColor);
+  controller_->ShowOneShotWallpaper(one_shot_wallpaper);
+  RunAllTasksUntilIdle();
+  EXPECT_EQ(1, GetWallpaperCount());
+  EXPECT_EQ(kOneShotWallpaperColor, GetWallpaperColor());
+  EXPECT_EQ(WallpaperType::ONE_SHOT, controller_->GetWallpaperType());
+  EXPECT_FALSE(controller_->IsBlurAllowed());
+  EXPECT_FALSE(controller_->ShouldApplyDimming());
+
+  // Verify the user wallpaper info is unaffected, and the one-shot wallpaper
+  // can be replaced by the user wallpaper.
+  EXPECT_TRUE(controller_->GetUserWallpaperInfo(account_id_1, &wallpaper_info,
+                                                false /*is_ephemeral=*/));
+  EXPECT_EQ(expected_wallpaper_info, wallpaper_info);
+  ClearWallpaperCount();
+  controller_->ShowUserWallpaper(InitializeUser(account_id_1));
+  RunAllTasksUntilIdle();
+  EXPECT_EQ(1, GetWallpaperCount());
+  EXPECT_EQ(kWallpaperColor, GetWallpaperColor());
+  EXPECT_EQ(WallpaperType::CUSTOMIZED, controller_->GetWallpaperType());
+}
+
 // A test wallpaper controller client class.
 class TestWallpaperControllerClient : public mojom::WallpaperControllerClient {
  public:

chrome/browser/ui/ash/test_wallpaper_controller.cc

@@ -126,6 +126,11 @@ void TestWallpaperController::ShowSigninWallpaper() {
   NOTIMPLEMENTED();
 }
 
+void TestWallpaperController::ShowOneShotWallpaper(
+    const gfx::ImageSkia& image) {
+  NOTIMPLEMENTED();
+}
+
 void TestWallpaperController::RemoveUserWallpaper(
     ash::mojom::WallpaperUserInfoPtr user_info,
     const std::string& wallpaper_files_id) {

chrome/browser/ui/ash/test_wallpaper_controller.h

@@ -85,6 +85,7 @@ class TestWallpaperController : ash::mojom::WallpaperController {
                                    ash::WallpaperLayout layout) override;
   void ShowUserWallpaper(ash::mojom::WallpaperUserInfoPtr user_info) override;
   void ShowSigninWallpaper() override;
+  void ShowOneShotWallpaper(const gfx::ImageSkia& image) override;
   void RemoveUserWallpaper(ash::mojom::WallpaperUserInfoPtr user_info,
                            const std::string& wallpaper_files_id) override;
   void RemovePolicyWallpaper(ash::mojom::WallpaperUserInfoPtr user_info,

chrome/browser/ui/ash/wallpaper_controller_client.cc

@@ -10,7 +10,6 @@
 #include "base/strings/string_number_conversions.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/chromeos/customization/customization_wallpaper_util.h"
-#include "chrome/browser/chromeos/login/startup_utils.h"
 #include "chrome/browser/chromeos/login/wizard_controller.h"
 #include "chrome/browser/chromeos/policy/device_local_account.h"
 #include "chrome/browser/extensions/extension_service.h"
@@ -21,6 +20,7 @@
 #include "chrome/common/extensions/extension_constants.h"
 #include "chromeos/chromeos_switches.h"
 #include "chromeos/cryptohome/system_salt_getter.h"
+#include "components/session_manager/core/session_manager.h"
 #include "components/user_manager/known_user.h"
 #include "components/user_manager/user_manager.h"
 #include "content/public/browser/notification_service.h"
@@ -440,7 +440,7 @@ void WallpaperControllerClient::OnDeviceWallpaperPolicyCleared() {
 }
 
 void WallpaperControllerClient::OnShowUserNamesOnLoginPolicyChanged() {
-  UpdateRegisteredDeviceWallpaper();
+  ShowWallpaperOnLoginScreen();
 }
 
 void WallpaperControllerClient::FlushForTesting() {
@@ -468,7 +468,7 @@ void WallpaperControllerClient::BindAndSetClient() {
       policy_handler_.IsDeviceWallpaperPolicyEnforced());
 }
 
-void WallpaperControllerClient::UpdateRegisteredDeviceWallpaper() {
+void WallpaperControllerClient::ShowWallpaperOnLoginScreen() {
   if (user_manager::UserManager::Get()->IsUserLoggedIn())
     return;
 
@@ -508,11 +508,6 @@ void WallpaperControllerClient::OpenWallpaperPicker() {
 }
 
 void WallpaperControllerClient::OnReadyToSetWallpaper() {
-  // TODO(wzang|784495): Consider deprecating this method after views-based
-  // login is enabled. It should be fast enough to request the first wallpaper
-  // so that there's no visible delay. In other scenarios such as restart after
-  // crash, user manager should request the wallpaper.
-
   // Apply device customization.
   namespace util = chromeos::customization_wallpaper_util;
   if (util::ShouldUseCustomizedDefaultWallpaper()) {
@@ -542,14 +537,18 @@ void WallpaperControllerClient::OnReadyToSetWallpaper() {
     return;
   }
 
-  // If the device is not registered yet (e.g. during OOBE), show the default
-  // signin wallpaper.
-  if (!chromeos::StartupUtils::IsDeviceRegistered()) {
-    ShowSigninWallpaper();
+  // Show a white wallpaper during OOBE.
+  if (session_manager::SessionManager::Get()->session_state() ==
+      session_manager::SessionState::OOBE) {
+    SkBitmap bitmap;
+    bitmap.allocN32Pixels(1, 1);
+    bitmap.eraseColor(SK_ColorWHITE);
+    wallpaper_controller_->ShowOneShotWallpaper(
+        gfx::ImageSkia::CreateFrom1xBitmap(bitmap));
     return;
   }
 
-  UpdateRegisteredDeviceWallpaper();
+  ShowWallpaperOnLoginScreen();
 }
 
 void WallpaperControllerClient::OnFirstWallpaperAnimationFinished() {

chrome/browser/ui/ash/wallpaper_controller_client.h

@@ -109,10 +109,14 @@ class WallpaperControllerClient : public ash::mojom::WallpaperControllerClient,
   // Binds this object to its mojo interface and sets it as the ash client.
   void BindAndSetClient();
 
-  // Updates the wallpaper of a registered device after device policy is
-  // trusted, outside an user session. Note that before device is enrolled, it
-  // proceeds with untrusted setting.
-  void UpdateRegisteredDeviceWallpaper();
+  // Shows the wallpaper of the first user in |UserManager::GetUsers|, or a
+  // default signin wallpaper if there's no user. This ensures the wallpaper is
+  // shown right after boot, regardless of when the login screen is available.
+  //
+  // TODO(wzang|784495): Consider deprecating this method after views-based
+  // login is enabled. It should be fast enough to request the first wallpaper
+  // so that there's no visible delay.
+  void ShowWallpaperOnLoginScreen();
 
   // ash::mojom::WallpaperControllerClient:
   void OpenWallpaperPicker() override;

tools/metrics/histograms/enums.xml

@@ -49600,6 +49600,7 @@ Full version information for the fingerprint enum values:
   <int value="5" label="Policy"/>
   <int value="6" label="Third party"/>
   <int value="7" label="Device policy"/>
+  <int value="8" label="One-shot"/>
 </enum>
 
 <enum name="WarmupStateOnLaunch">