Register and select printer on click.

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

Index: chrome/browser/ui/webui/print_preview/printer_backend_proxy.cc
diff --git a/chrome/browser/ui/webui/print_preview/printer_backend_proxy.cc b/chrome/browser/ui/webui/print_preview/printer_backend_proxy.cc
index 3a92bc0cf555891dbd7a91d8737280ba8155fcd5..effbb06c0d45e3532ef7a9dc6ff37666ed58006a 100644
--- a/chrome/browser/ui/webui/print_preview/printer_backend_proxy.cc
+++ b/chrome/browser/ui/webui/print_preview/printer_backend_proxy.cc
@@ -5,9 +5,12 @@
 #include "chrome/browser/ui/webui/print_preview/printer_backend_proxy.h"
 
 #include <string>
+#include <utility>
 
 #include "base/logging.h"
+#include "base/memory/ptr_util.h"
 #include "base/memory/ref_counted.h"
+#include "chrome/browser/ui/webui/print_preview/printer_capabilities.h"
 #include "content/public/browser/browser_thread.h"
 #include "printing/backend/print_backend.h"
 
@@ -27,6 +30,28 @@ PrinterList EnumeratePrintersOnBlockingPoolThread() {
   return printer_list;
 }
 
+std::unique_ptr<base::DictionaryValue> FetchCapabilitiesOnBlockingPool(
+    const std::string& device_name) {
+  DCHECK(content::BrowserThread::GetBlockingPool()->RunsTasksOnCurrentThread());
+  scoped_refptr<printing::PrintBackend> print_backend(
+      printing::PrintBackend::CreateInstance(nullptr));
+
+  VLOG(1) << "Get printer capabilities start for " << device_name;
+
+  std::unique_ptr<base::DictionaryValue> printer_info;
+  if (!print_backend->IsValidPrinter(device_name)) {
+    LOG(WARNING) << "Invalid printer " << device_name;
+    return nullptr;
+  }
+
+  PrinterBasicInfo basic_info;
+  if (!print_backend->GetPrinterBasicInfo(device_name, &basic_info)) {
+    return nullptr;
+  }
+
+  return GetSettingsOnBlockingPool(device_name, basic_info);
+}
+
 }  // namespace
 
 std::string GetDefaultPrinterOnBlockingPoolThread() {
@@ -47,4 +72,14 @@ void EnumeratePrinters(Profile* /* profile */,
       base::Bind(&EnumeratePrintersOnBlockingPoolThread), cb);
 }
 
+void ConfigurePrinterAndFetchCapabilities(Profile* /* profile */,
+                                          const std::string& device_name,
+                                          const PrinterSetupCallback& cb) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
+  base::PostTaskAndReplyWithResult(
+      content::BrowserThread::GetBlockingPool(), FROM_HERE,
+      base::Bind(&FetchCapabilitiesOnBlockingPool, device_name), cb);
+}
+
 }  // namespace printing