Get semantic capabilities from Print Backend.

printing/backend/print_backend.cc

Index: printing/backend/print_backend.cc
===================================================================
--- printing/backend/print_backend.cc	(revision 153539)
+++ printing/backend/print_backend.cc	(working copy)
@@ -6,12 +6,29 @@
 
 namespace printing {
 
+static const char kSemanticCapabilities[] = "capabilities";
+static const char kSemanticDefaults[] = "defaults";
+static const char kSemanticColor[] = "color";
+static const char kSemanticDuplex[] = "duplex";
+
 PrinterBasicInfo::PrinterBasicInfo()
     : printer_status(0),
       is_default(false) {}
 
 PrinterBasicInfo::~PrinterBasicInfo() {}
 
+PrinterSemanticCapsAndDefaults::PrinterSemanticCapsAndDefaults()
+    : color_capable(false),
+      duplex_capable(false),
+      color_default(false),
+      duplex_default(UNKNOWN_DUPLEX_MODE) {}
+
+PrinterSemanticCapsAndDefaults::~PrinterSemanticCapsAndDefaults() {}
+
+std::string PrinterSemanticCapsAndDefaults::GetAsJson() const {
+  return "Not yet implemented";
+}
+
 PrinterCapsAndDefaults::PrinterCapsAndDefaults() {}
 
 PrinterCapsAndDefaults::~PrinterCapsAndDefaults() {}