Add learn more link to TPM firmware update option

This adds a learn more link to the TPM firmware update option on the device
reset aka powerwash OOBE screen.

BUG=chromium:767900
TEST=Manual

Change-Id: Iaaeb7c63f877b0b0d6e8e5fb3073a04eec3bd3e8
Reviewed-on: https://chromium-review.googlesource.com/682694Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Mattias Nissler <mnissler@chromium.org>
Cr-Commit-Position: refs/heads/master@{#504206}

chrome/browser/chromeos/login/help_app_launcher.h

@@ -35,6 +35,8 @@ class HelpAppLauncher : public base::RefCountedThreadSafe<HelpAppLauncher> {
     HELP_POWERWASH = 183084,
     // Shown as "Learn more" about the device attributes.
     HELP_DEVICE_ATTRIBUTES = 6218780,
+    // Shown as "Learn more" for TPM firmware udpate option in reset screen.
+    HELP_TPM_FIRMWARE_UPDATE = 7507584,
   };
 
   // The dialog is shown as a child of |parent_window|. If |parent_window| is

chrome/browser/chromeos/login/screens/reset_screen.cc

@@ -37,6 +37,8 @@ constexpr const char kUserActionResetShowConfirmationPressed[] =
     "show-confirmation";
 constexpr const char kUserActionResetResetConfirmationDismissed[] =
     "reset-confirm-dismissed";
+constexpr const char kUserActionTPMFirmwareUpdateLearnMore[] =
+    "tpm-firmware-update-learn-more-link";
 
 constexpr const char kContextKeyIsRollbackAvailable[] = "rollback-available";
 constexpr const char kContextKeyIsRollbackChecked[] = "rollback-checked";
@@ -159,13 +161,15 @@ void ResetScreen::OnUserAction(const std::string& action_id) {
   else if (action_id == kUserActionResetPowerwashPressed)
     OnPowerwash();
   else if (action_id == kUserActionResetLearnMorePressed)
-    OnLearnMore();
+    ShowHelpArticle(HelpAppLauncher::HELP_POWERWASH);
   else if (action_id == kUserActionResetRollbackToggled)
     OnToggleRollback();
   else if (action_id == kUserActionResetShowConfirmationPressed)
     OnShowConfirm();
   else if (action_id == kUserActionResetResetConfirmationDismissed)
     OnConfirmationDismissed();
+  else if (action_id == kUserActionTPMFirmwareUpdateLearnMore)
+    ShowHelpArticle(HelpAppLauncher::HELP_TPM_FIRMWARE_UPDATE);
   else
     BaseScreen::OnUserAction(action_id);
 }
@@ -257,21 +261,21 @@ void ResetScreen::OnShowConfirm() {
   GetContextEditor().SetBoolean(kContextKeyIsConfirmational, true);
 }
 
-void ResetScreen::OnLearnMore() {
+void ResetScreen::OnConfirmationDismissed() {
+  GetContextEditor().SetBoolean(kContextKeyIsConfirmational, false);
+}
+
+void ResetScreen::ShowHelpArticle(HelpAppLauncher::HelpTopic topic) {
 #if defined(OFFICIAL_BUILD)
-  VLOG(1) << "Trying to view the help article about reset options.";
+  VLOG(1) << "Trying to view help article " << topic;
   if (!help_app_.get()) {
     help_app_ = new HelpAppLauncher(
         LoginDisplayHost::default_host()->GetNativeWindow());
   }
-  help_app_->ShowHelpTopic(HelpAppLauncher::HELP_POWERWASH);
+  help_app_->ShowHelpTopic(topic);
 #endif
 }
 
-void ResetScreen::OnConfirmationDismissed() {
-  GetContextEditor().SetBoolean(kContextKeyIsConfirmational, false);
-}
-
 void ResetScreen::UpdateStatusChanged(
     const UpdateEngineClient::Status& status) {
   VLOG(1) << "Update status change to " << status.status;

chrome/browser/chromeos/login/screens/reset_screen.h

@@ -59,9 +59,10 @@ class ResetScreen : public BaseScreen, public UpdateEngineClient::Observer {
   void OnRestart();
   void OnToggleRollback();
   void OnShowConfirm();
-  void OnLearnMore();
   void OnConfirmationDismissed();
 
+  void ShowHelpArticle(HelpAppLauncher::HelpTopic topic);
+
   // Returns an instance of the error screen.
   ErrorScreen* GetErrorScreen();
 

chrome/browser/resources/chromeos/login/oobe_reset.css

@@ -45,3 +45,8 @@ a {
   -webkit-margin-start: 16px;
   line-height: 20px;
 }
+
+#tpmFirmwareUpdateContainer a {
+  cursor: pointer;
+  pointer-events: auto;
+}

chrome/browser/resources/chromeos/login/oobe_reset.html

@@ -74,6 +74,9 @@
               on-change="onTPMFirmwareUpdateChanged_">
             <div id="tpmFirmwareUpdateContainer">
               <span i18n-content="resetTPMFirmwareUpdate"></span>
+              <a href="#" hidden="[[isHelpLinkHidden_(uiState_, isOfficial_)]]"
+                  on-tap="onTPMFirmwareUpdateLearnMore_"
+                  i18n-content="learnMore"></a>
             </div>
           </paper-checkbox>
         </div>

chrome/browser/resources/chromeos/login/oobe_reset.js

@@ -113,4 +113,17 @@ Polymer({
     this.screen.onTPMFirmwareUpdateChanged_(
         this.$.tpmFirmwareUpdateCheckbox.checked);
   },
+
+  /**
+   * On-tap event handler for the TPM firmware update learn more link.
+   *
+   * @param {!Event} event
+   * @private
+   */
+  onTPMFirmwareUpdateLearnMore_: function(event) {
+    chrome.send(
+        'login.ResetScreen.userActed', ['tpm-firmware-update-learn-more-link']);
+    event.stopPropagation();
+  },
+
 });