Add OpenVR SDK to third_party

third_party/openvr/src/src/vrcommon/vrpathregistry_public.h

Index: third_party/openvr/src/src/vrcommon/vrpathregistry_public.h
diff --git a/third_party/openvr/src/src/vrcommon/vrpathregistry_public.h b/third_party/openvr/src/src/vrcommon/vrpathregistry_public.h
new file mode 100644
index 0000000000000000000000000000000000000000..1386c75cb5125f4d5845da824fda38e7eef02a1b
--- /dev/null
+++ b/third_party/openvr/src/src/vrcommon/vrpathregistry_public.h
@@ -0,0 +1,45 @@
+//========= Copyright Valve Corporation ============//
+#pragma once
+
+#include <string>
+#include <vector>
+#include <stdint.h>
+
+static const char *k_pchRuntimeOverrideVar = "VR_OVERRIDE";
+static const char *k_pchConfigOverrideVar = "VR_CONFIG_PATH";
+static const char *k_pchLogOverrideVar = "VR_LOG_PATH";
+
+class CVRPathRegistry_Public
+{
+public:
+	static std::string GetVRPathRegistryFilename();
+	static std::string GetOpenVRConfigPath();
+
+public:
+	CVRPathRegistry_Public();
+
+	/** Returns paths using the path registry and the provided override values. Pass NULL for any paths you don't care about. 
+	* Returns false if the path registry could not be read. Valid paths might still be returned based on environment variables. */
+	static bool GetPaths( std::string *psRuntimePath, std::string *psConfigPath, std::string *psLogPath, const char *pchConfigPathOverride, const char *pchLogPathOverride, std::vector<std::string> *pvecExternalDrivers = NULL );
+
+	bool BLoadFromFile();
+	bool BSaveToFile() const;
+
+	bool ToJsonString( std::string &sJsonString );
+
+	// methods to get the current values
+	std::string GetRuntimePath() const;
+	std::string GetConfigPath() const;
+	std::string GetLogPath() const;
+
+protected:
+	typedef std::vector< std::string > StringVector_t;
+
+	// index 0 is the current setting
+	StringVector_t m_vecRuntimePath;
+	StringVector_t m_vecLogPath;
+	StringVector_t m_vecConfigPath;
+
+	// full list of external drivers
+	StringVector_t m_vecExternalDrivers;
+};