Include USB printers in printer list as "provisional" devices.

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

 // Copyright (c) 2012 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 "chrome/browser/ui/webui/print_preview/print_preview_handler.h"
 
 #include <ctype.h>
 
 #include <map>
 #include <string>
 
 #include "base/base64.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/i18n/file_util_icu.h"
 #include "base/i18n/number_formatting.h"
 #include "base/json/json_reader.h"
 #include "base/lazy_instance.h"
 #include "base/memory/linked_ptr.h"
 #include "base/memory/ref_counted_memory.h"
 #include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/prefs/pref_service.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread.h"
 #include "base/threading/thread_restrictions.h"
+#include "base/threading/worker_pool.h"
 #include "base/values.h"
 #include "chrome/browser/app_mode/app_mode_utils.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/platform_util.h"
 #include "chrome/browser/printing/print_dialog_cloud.h"
 #include "chrome/browser/printing/print_error_dialog.h"
 #include "chrome/browser/printing/print_job_manager.h"
 #include "chrome/browser/printing/print_preview_dialog_controller.h"
 #include "chrome/browser/printing/print_view_manager.h"
 #include "chrome/browser/printing/printer_manager_dialog.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/signin/gaia_cookie_manager_service_factory.h"
 #include "chrome/browser/signin/profile_oauth2_token_service_factory.h"
 #include "chrome/browser/signin/signin_manager_factory.h"
 #include "chrome/browser/ui/browser_finder.h"
 #include "chrome/browser/ui/browser_tabstrip.h"
 #include "chrome/browser/ui/chrome_select_file_policy.h"
 #include "chrome/browser/ui/scoped_tabbed_browser_displayer.h"
+#include "chrome/browser/ui/webui/print_preview/extension_printer_handler.h"
 #include "chrome/browser/ui/webui/print_preview/print_preview_ui.h"
 #include "chrome/browser/ui/webui/print_preview/printer_handler.h"
 #include "chrome/browser/ui/webui/print_preview/sticky_settings.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/cloud_print/cloud_print_cdd_conversion.h"
 #include "chrome/common/cloud_print/cloud_print_constants.h"
 #include "chrome/common/crash_keys.h"
 #include "chrome/common/pref_names.h"
 #include "components/cloud_devices/common/cloud_device_description.h"
@@ skipping 602 matching lines @@
       base::Bind(&PrintPreviewHandler::HandleStopGetPrivetPrinters,
                  base::Unretained(this)));
   web_ui()->RegisterMessageCallback("getPrivetPrinterCapabilities",
       base::Bind(&PrintPreviewHandler::HandleGetPrivetPrinterCapabilities,
                  base::Unretained(this)));
   web_ui()->RegisterMessageCallback(
       "getExtensionPrinters",
       base::Bind(&PrintPreviewHandler::HandleGetExtensionPrinters,
                  base::Unretained(this)));
   web_ui()->RegisterMessageCallback(
+      "getExtensionUsbPrinters",
+      base::Bind(&PrintPreviewHandler::HandleGetExtensionUsbPrinters,
+                 base::Unretained(this)));
+  web_ui()->RegisterMessageCallback(
       "getExtensionPrinterCapabilities",
       base::Bind(&PrintPreviewHandler::HandleGetExtensionPrinterCapabilities,
                  base::Unretained(this)));
   RegisterForGaiaCookieChanges();
 }
 
 bool PrintPreviewHandler::PrivetPrintingEnabled() {
 #if defined(ENABLE_SERVICE_DISCOVERY)
   return true;
 #else
@@ skipping 57 matching lines @@
 void PrintPreviewHandler::HandleGetExtensionPrinters(
     const base::ListValue* args) {
   EnsureExtensionPrinterHandlerSet();
   // Make sure all in progress requests are canceled before new printer search
   // starts.
   extension_printer_handler_->Reset();
   extension_printer_handler_->StartGetPrinters(base::Bind(
       &PrintPreviewHandler::OnGotPrintersForExtension, base::Unretained(this)));
 }
 
+void PrintPreviewHandler::HandleGetExtensionUsbPrinters(
+    const base::ListValue* args) {
+  extension_printer_handler_->StartGetUsbPrinters(base::Bind(

[Vitaly Buka (NO REVIEWS), 2015/05/27 16:58:40]

Can you avoid adding this function and remove as mach as possible 
USB related logic from PrintPreview.
I guess you can return combined list from
extension_printer_handler_->StartGetPrinters

[Vitaly Buka (NO REVIEWS), 2015/05/27 17:14:16]

I am asking because every new type of printers cause a lot of small changes in
different places of the preview JS.
I guess the only USB specific thing you need is a message for printers what
where never selected for users.

Also call you call that message some how generic? Something like "Printer
selection confirmation"
So if message is present, preview will ask user for any type of printers.

If HandleGetExtensionPrinterCapabilities is called after that,
extension_printer_handler_ will knows that user allowed access.

[Reilly Grant (use Gerrit), 2015/05/28 21:45:00]

Done.

+      &PrintPreviewHandler::OnGotExtensionUsbPrinters, base::Unretained(this)));
+}
+
 void PrintPreviewHandler::HandleGetExtensionPrinterCapabilities(
     const base::ListValue* args) {
   std::string printer_id;
   bool ok = args->GetString(0, &printer_id);
   DCHECK(ok);
 
   EnsureExtensionPrinterHandlerSet();
   extension_printer_handler_->StartGetCapability(
       printer_id,
       base::Bind(&PrintPreviewHandler::OnGotExtensionPrinterCapabilities,
@@ skipping 919 matching lines @@
   printer_value->SetBoolean(
       "isUnregistered",
       description.id.empty() &&
       command_line->HasSwitch(switches::kEnablePrintPreviewRegisterPromos));
   printer_value->SetString("cloudID", description.id);
 }
 
 #endif  // defined(ENABLE_SERVICE_DISCOVERY)
 
 void PrintPreviewHandler::EnsureExtensionPrinterHandlerSet() {
-  if (extension_printer_handler_.get())
-    return;
-
-  extension_printer_handler_ =
-      PrinterHandler::CreateForExtensionPrinters(Profile::FromWebUI(web_ui()));
+  if (!extension_printer_handler_.get()) {

[Vitaly Buka (NO REVIEWS), 2015/05/27 16:58:40]

if (extension_printer_handler_)

[Reilly Grant (use Gerrit), 2015/05/28 21:45:00]

Done.

+    extension_printer_handler_.reset(new ExtensionPrinterHandler(
+        Profile::FromWebUI(web_ui()), base::WorkerPool::GetTaskRunner(true)));
+  }
 }
 
 void PrintPreviewHandler::OnGotPrintersForExtension(
     const base::ListValue& printers,
     bool done) {
   web_ui()->CallJavascriptFunction("onExtensionPrintersAdded", printers,
                                    base::FundamentalValue(done));
 }
 
+void PrintPreviewHandler::OnGotExtensionUsbPrinters(
+    const base::ListValue& printers) {
+  web_ui()->CallJavascriptFunction("onExtensionUsbPrintersAdded", printers);
+}
+
 void PrintPreviewHandler::OnGotExtensionPrinterCapabilities(
     const std::string& printer_id,
     const base::DictionaryValue& capabilities) {
   if (capabilities.empty()) {
     web_ui()->CallJavascriptFunction("failedToGetExtensionPrinterCapabilities",
                                      base::StringValue(printer_id));
     return;
   }
 
   web_ui()->CallJavascriptFunction("onExtensionCapabilitiesSet",
@@ skipping 26 matching lines @@
 
 void PrintPreviewHandler::UnregisterForGaiaCookieChanges() {
   if (gaia_cookie_manager_service_)
     gaia_cookie_manager_service_->RemoveObserver(this);
 }
 
 void PrintPreviewHandler::SetPdfSavedClosureForTesting(
     const base::Closure& closure) {
   pdf_file_saved_closure_ = closure;
 }