Add GL strings to CastSysInfo interface and use to configure GPU

chromecast/base/cast_sys_info_dummy.cc

Index: chromecast/base/cast_sys_info_dummy.cc
diff --git a/chromecast/base/cast_sys_info_dummy.cc b/chromecast/base/cast_sys_info_dummy.cc
index 92c39a952c0127716deb403b20674722ac2496c4..0bacf143adaf89846bab2cd01abdced64d8b0787 100644
--- a/chromecast/base/cast_sys_info_dummy.cc
+++ b/chromecast/base/cast_sys_info_dummy.cc
@@ -64,4 +64,12 @@ std::string CastSysInfoDummy::GetApInterface() {
   return "";
 }
 
+std::string CastSysInfoDummy::GetGpuVendor() {
+  return "";
+}
+
+std::string CastSysInfoDummy::GetGpuModel() {
+  return "";
+}
+
 }  // namespace chromecast