Update CUPS settings UI to allow USB printers to be added via discovery.

chrome/browser/resources/settings/printing_page/cups_add_printer_dialog.html

 <link rel="import" href="chrome://resources/html/md_select_css.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/html/web_ui_listener_behavior.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-input/paper-input.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-spinner/paper-spinner.html">
 <link rel="import" href="../i18n_setup.html">
 <link rel="import" href="cups_add_printer_dialog_util.html">
 <link rel="import" href="cups_printers_browser_proxy.html">
 <link rel="import" href="../settings_shared_css.html">
@@ skipping 57 matching lines @@
             $i18n{manuallyAddPrinterButtonText}
           </paper-button>
         </div>
         <div>  <!-- Right group -->
           <paper-button class="cancel-button secondary-button"
               on-tap="onCancelTap_">
             $i18n{cancelButtonText}
           </paper-button>
           <paper-button class="action-button" id="addPrinterButton"
               disabled="[[!selectedPrinter]]"
-              on-tap="switchToConfiguringDialog_">
+              on-tap="switchToManufacturerDialog_">
             $i18n{addPrinterButtonText}
           </paper-button>
         </div>
       </div>
     </add-printer-dialog>
   </template>
 </dom-module>
 
 <dom-module id="add-printer-manually-dialog">
   <template>
@@ skipping 220 matching lines @@
             </div>
           </div>
         </div>
         <div class="error-message" hidden="[[!setupFailed]]">
           Driver not found (exact error message TBD)
         </div>
       </div>
       <div class="dialog-buttons">
         <div>  <!-- Left group -->
           <paper-button id="manuallyAddPrinterButton" class="secondary-button"
-              on-tap="switchToManualAddDialog_">
-            $i18n{manuallyAddPrinterButtonText}
+              on-tap="switchToManualAddDialog_" hidden="[[!inManualFlow]]">
+            $i18n{back}
           </paper-button>
         </div>
         <div>  <!-- Right group -->
           <paper-button class="cancel-button secondary-button"
               on-tap="onCancelTap_">
             $i18n{cancelButtonText}
           </paper-button>
           <paper-button class="action-button" id="addPrinterButton"
               on-tap="switchToConfiguringDialog_">
             $i18n{addPrinterButtonText}
@@ skipping 27 matching lines @@
     </add-printer-dialog>
   </template>
 </dom-module>
 
 <dom-module id="settings-cups-add-printer-dialog">
   <template>
     <style include="settings-shared"></style>
 
     <!-- Printer Discovery Dialog -->
     <template is="dom-if" if="[[showDiscoveryDialog_]]" restamp>
-      <add-printer-discovery-dialog selected-printer="{{selectedPrinter}}">
+      <add-printer-discovery-dialog selected-printer="{{selectedPrinter}}"
+                                    new-printer="{{newPrinter}}">
       </add-printer-discovery-dialog>
     </template>
 
     <!-- Manually Add Printer Dialog -->
     <template is="dom-if" if="[[showManuallyAddDialog_]]" restamp>
       <add-printer-manually-dialog new-printer="{{newPrinter}}">
       </add-printer-manually-dialog>
     </template>
 
     <!-- Configuring Printer Dialog -->
     <template is="dom-if" if="[[showConfiguringDialog_]]" restamp>
       <add-printer-configuring-dialog
           printer-name="[[getConfiguringPrinterName_()]]"
           dialog-title="[[configuringDialogTitle]]">
       </add-printer-configuring-dialog>
     </template>
 
     <!-- Manufacturer and Model Dialog -->
     <template is="dom-if" if="[[showManufacturerDialog_]]" restamp>
       <add-printer-manufacturer-model-dialog new-printer="{{newPrinter}}"
-          setup-failed="[[setupFailed]]">
+          setup-failed="[[setupFailed]]" in-manual-flow="[[inManualFlow]]">
       </add-printer-manufacturer-model-dialog>
     </template>
 
   </template>
   <script src="cups_add_printer_dialog.js"></script>
 </dom-module>