List printers managed by extensions in print preview

chrome/browser/resources/print_preview/native_layer.js

Index: chrome/browser/resources/print_preview/native_layer.js
diff --git a/chrome/browser/resources/print_preview/native_layer.js b/chrome/browser/resources/print_preview/native_layer.js
index d4beb8926afb27fd2400ba4f8f52f222d76fc2be..57b73bfd32479953afff2728d6356b4700df8b0b 100644
--- a/chrome/browser/resources/print_preview/native_layer.js
+++ b/chrome/browser/resources/print_preview/native_layer.js
@@ -57,6 +57,10 @@ cr.define('print_preview', function() {
     global.onPrivetCapabilitiesSet =
         this.onPrivetCapabilitiesSet_.bind(this);
     global.onPrivetPrintFailed = this.onPrivetPrintFailed_.bind(this);
+    global.onExtensionPrintersAdded =
+        this.onExtensionPrintersAdded_.bind(this);
+    global.onExtensionCapabilitiesSet =
+        this.onExtensionCapabilitiesSet_.bind(this);
     global.onEnableManipulateSettingsForTest =
         this.onEnableManipulateSettingsForTest_.bind(this);
     global.printPresetOptionsFromDocument =
@@ -95,6 +99,10 @@ cr.define('print_preview', function() {
     PRIVET_CAPABILITIES_SET:
         'print_preview.NativeLayer.PRIVET_CAPABILITIES_SET',
     PRIVET_PRINT_FAILED: 'print_preview.NativeLayer.PRIVET_PRINT_FAILED',
+    EXTENSION_PRINTERS_ADDED:
+        'print_preview.NativeLayer.EXTENSION_PRINTERS_ADDED',
+    EXTENSION_CAPABILITIES_SET:
+        'print_preview.NativeLayer.EXTENSION_CAPABILITIES_SET',
     PRINT_PRESET_OPTIONS: 'print_preview.NativeLayer.PRINT_PRESET_OPTIONS',
   };
 
@@ -177,6 +185,26 @@ cr.define('print_preview', function() {
     },
 
     /**
+     * Requests that extension system dispatches an event requesting the list of
+     * extension managed printers.
+     */
+    startGetExtensionDestinations: function() {
+      chrome.send('getExtensionPrinters');
+    },
+
+    /**
+     * Requests an extension destination's printing capabilities. A
+     * EXTENSION_CAPABILITIES_SET event will be dispatched in response.
+     * @param {string} extensionId The ID of the extension from which the
+     *     capabilities should be requested.
+     * @param {string} printerId The ID of the printer whose capabilities are
+     *     requested.
+     */
+    startGetExtensionDestinationCapabilities: function(extensionId, printerId) {
+      chrome.send('getExtensionPrinterCapabilities', [extensionId, printerId]);
+    },
+
+    /**
      * Requests the destination's printing capabilities. A CAPABILITIES_SET
      * event will be dispatched in response.
      * @param {string} destinationId ID of the destination.
@@ -299,6 +327,10 @@ cr.define('print_preview', function() {
       assert(!opt_showSystemDialog || (cr.isWindows && destination.isLocal),
              'Implemented for Windows only');
 
+      // TODO(tbarzic): Implement this.
+      assert(!destination.isExtension,
+             'Printing to extension printers not yet implemented.');
+
       var ticket = {
         'pageRange': printTicketStore.pageRange.getDocumentPageRanges(),
         'mediaSize': printTicketStore.mediaSize.getValue(),
@@ -720,6 +752,40 @@ cr.define('print_preview', function() {
     },
 
     /**
+     * @param {Array.<{extensionId: string,
+     *                 id: string,
+     *                 name: string,
+     *                 description: (string|undefined)}>} printers The list
+     *     containing information about printers added by an extension.
+     * @param {boolean} done Whether this is the final list of extension
+     *     managed printers.
+     */
+    onExtensionPrintersAdded_: function(printers, done) {
+      var event = new Event(NativeLayer.EventType.EXTENSION_PRINTERS_ADDED);
+      event.printers = printers;
+      event.done = done;
+      this.dispatchEvent(event);
+    },
+
+    /**
+     * Called when an extension responds to a request for an extension printer
+     * capabilities.
+     * @param {string} extensionId The ID of extension that manages the printer.
+     * @param {string} printerId The printer's ID (within the extension's
+     *     space).
+     * @param {Object} capabilities The reported printer capabilities.
+     */
+    onExtensionCapabilitiesSet_: function(extensionId,
+                                          printerId,
+                                          capabilities) {
+      var event = new Event(NativeLayer.EventType.EXTENSION_CAPABILITIES_SET);
+      event.extensionID = extensionId;
+      event.printerID = printerId;
+      event.capabilities = capabilities;
+      this.dispatchEvent(event);
+    },
+
+   /**
      * Allows for onManipulateSettings to be called
      * from the native layer.
      * @private