Added PrinterDriverInfo and PrintBackend::GetPrinterDriverInfo for windows.

printing/backend/print_backend_cups.cc

Index: printing/backend/print_backend_cups.cc
diff --git a/printing/backend/print_backend_cups.cc b/printing/backend/print_backend_cups.cc
index d5433898fef332512ebc805d9b0fc8148387aa84..d43c3e32e0833e230dca29d643ccdeb46af02734 100644
--- a/printing/backend/print_backend_cups.cc
+++ b/printing/backend/print_backend_cups.cc
@@ -113,6 +113,9 @@ class PrintBackendCUPS : public PrintBackend {
       const std::string& printer_name,
       PrinterCapsAndDefaults* printer_info) OVERRIDE;
 
+  virtual bool GetPrinterDriverInfo(const std::string& printer_name,
+                                    PrinterDriverInfo* driver_info) OVERRIDE;
+
   virtual bool IsValidPrinter(const std::string& printer_name) OVERRIDE;
 
  private:
@@ -225,6 +228,12 @@ bool PrintBackendCUPS::GetPrinterCapsAndDefaults(
   return res;
 }
 
+bool PrintBackendCUPS::GetPrinterDriverInfo(const std::string& printer_name,
+                                            PrinterDriverInfo* driver_info) {
+  // TODO(vitalybuka): implement this.
+  return false;
+}
+
 bool PrintBackendCUPS::IsValidPrinter(const std::string& printer_name) {
   // This is not very efficient way to get specific printer info. CUPS 1.4
   // supports cupsGetNamedDest() function. However, CUPS 1.4 is not available