UI rework for reset options including Rollback.

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

 <div class="step faded hidden no-logo" id="reset" role="group" hidden
      i18n-values="aria-label:resetScreenAccessibleTitle">
   <div class="step-contents">
     <div id="reset-warning-msg" i18n-content="resetWarningTitle"
         class="revert-promise-specific restart-required-specific
-               powerwash-proposal-specific">
+               powerwash-proposal-specific rollback-proposal-specific">
     </div>
-    <div id="powerwash-warning-msg"
-        i18n-content="resetPowerwashWarningTitle"
-        class="powerwash-confirm-specific">
-    </div>
-    <div id="powerwash-and-rollback-warning-msg"
-        i18n-content="resetPowerwasAndRollbackhWarningTitle"
-        class="rollback-confirm-specific"></div>
     <img id="reset-warning-icon" src="chrome://theme/IDR_RESET_WARNING"
         i18n-values="alt:resetScreenIconTitle">
     <div id="reset-info"
-        class="reset-text powerwash-proposal-specific powerwash-confirm-specific
-               rollback-confirm-specific restart-required-specific">
+        class="reset-text powerwash-proposal-specific rollback-proposal-specific
+               restart-required-specific">
       <div id="powerwash-warning-details"
           i18n-content="resetPowerwashWarningDetails"
           class="powerwash-proposal-specific">
       </div>
-      <div id="powerwash-confirmation-details"
-          i18n-content="resetPowerwashConfirmationDetails"
-          class="reset-text powerwash-confirm-specific">
+      <div id="rollback-warning-details"
+          i18n-content="resetPowerwashRollbackWarningDetails"
+          class="rollback-proposal-specific">
       </div>
-      <div id="powerwash-and-rollback-confirmation-details"
-          i18n-content="resetPowerwashRollbackConfirmationDetails"
-          class="reset-text rollback-confirm-specific"></div>
       <div id="reset-warning-data-details"
           class="reset-text powerwash-proposal-specific
-                 powerwash-confirm-specific rollback-confirm-specific"
+                 rollback-proposal-specific"
           i18n-content="resetWarningDataDetails">
       </div>
       <div id="reset-warning-restart" i18n-content="resetRestartMessage"
            class="reset-text restart-required-specific">
       </div>
       <a id="powerwash-help-link" href="#" i18n-content="learnMore"></a>
     </div>
     <div id="revert-promise" class="revert-promise-specific">
       <div id="reset-revert-promise-msg" i18n-content="resetRevertPromise">
       </div>
       <div id="reset-revert-spinner" class="throbber">
       </div>
       <div id="reset-revert-spinner-message" class="reset-text"
            i18n-content="resetRevertSpinnerMessage">
       </div>
     </div>
   </div>
   <div id="reset-controls" class="step-controls"></div>
 </div>