Register and select printer on click.

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

Index: chrome/browser/ui/webui/print_preview/printer_backend_proxy.h
diff --git a/chrome/browser/ui/webui/print_preview/printer_backend_proxy.h b/chrome/browser/ui/webui/print_preview/printer_backend_proxy.h
index d28413a0d0629e35fa66156117c8cf1b7c684cd5..d2dff83b71a1bfb6e069101fccaa9d6a2fb1d897 100644
--- a/chrome/browser/ui/webui/print_preview/printer_backend_proxy.h
+++ b/chrome/browser/ui/webui/print_preview/printer_backend_proxy.h
@@ -18,6 +18,9 @@ namespace printing {
 
 using EnumeratePrintersCallback = base::Callback<void(const PrinterList&)>;
 
+using PrinterSetupCallback =
+    base::Callback<void(std::unique_ptr<base::DictionaryValue>)>;
+
 // Returns the name of the default printer.
 std::string GetDefaultPrinterOnBlockingPoolThread();
 
@@ -25,6 +28,13 @@ std::string GetDefaultPrinterOnBlockingPoolThread();
 // list.  This method expects to be called on the UI thread.
 void EnumeratePrinters(Profile* profile, const EnumeratePrintersCallback& cb);
 
+// Verifies printer setup if needed then retrieves printer capabilities for
+// |printer_name|.  |cb| is called with the capabilities dictionary or nullptr
+// if one of the steps failed.
+void ConfigurePrinterAndFetchCapabilities(Profile* profile,
+                                          const std::string& printer_name,
+                                          const PrinterSetupCallback& cb);
+
 }  // namespace printing
 
 #endif  // CHROME_BROWSER_UI_WEBUI_PRINT_PREVIEW_PRINTER_BACKEND_PROXY_H_