Add onGetUsbPrinterInfoRequested event to printerProvider API.

chrome/browser/ui/webui/print_preview/extension_printer_handler_unittest.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
@@ skipping 337 matching lines @@
   void DispatchPrintRequested(
       const PrinterProviderPrintJob& job,
       const PrinterProviderAPI::PrintCallback& callback) override {
     PrintRequestInfo request_info;
     request_info.callback = callback;
     request_info.job = job;
 
     pending_print_requests_.push_back(request_info);
   }
 
+  void DispatchGetUsbPrinterInfoRequested(
+      const std::string& extension_id,
+      scoped_refptr<device::UsbDevice> device,
+      const PrinterProviderAPI::GetPrinterInfoCallback& callback) override {
+    ADD_FAILURE() << "Not reached.";
+  }
+
   size_t pending_get_printers_count() const {
     return pending_printers_callbacks_.size();
   }
 
   const PrinterProviderPrintJob* GetPrintJob(
       const extensions::Extension* extension,
       int request_id) const override {
     ADD_FAILURE() << "Not reached";
     return nullptr;
   }
@@ skipping 554 matching lines @@
   extension_printer_handler_->StartPrint(
       kPrinterId, kPWGRasterOnlyPrinterSimpleDescription, title,
       kEmptyPrintTicket, gfx::Size(100, 100), print_data,
       base::Bind(&RecordPrintResult, &call_count, &success, &status));
 
   EXPECT_EQ(1u, call_count);
 
   EXPECT_FALSE(success);
   EXPECT_EQ("INVALID_DATA", status);
 }