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..57e8beae188669ab979a00813cc55b06404a982d 100644
--- a/chromecast/base/cast_sys_info_dummy.cc
+++ b/chromecast/base/cast_sys_info_dummy.cc
@@ -64,4 +64,16 @@ std::string CastSysInfoDummy::GetApInterface() {
   return "";
 }
 
+std::string CastSysInfoDummy::GetGlVendor() {
+  return "";
+}
+
+std::string CastSysInfoDummy::GetGlRenderer() {
+  return "";
+}
+
+std::string CastSysInfoDummy::GetGlVersion() {
+  return "";
+}
+
 }  // namespace chromecast