Moving the GL implementation details into a sub folder for client display.

remoting/client/display/gl_math.h

Index: remoting/client/display/gl_math.h
diff --git a/remoting/client/gl_math.h b/remoting/client/display/gl_math.h
similarity index 90%
rename from remoting/client/gl_math.h
rename to remoting/client/display/gl_math.h
index cc8fc1b12abc92e1d961d94c28b2b60eac6fd419..184d37cf8c55b0bdaecef62eb396b97cee4c98a0 100644
--- a/remoting/client/gl_math.h
+++ b/remoting/client/display/gl_math.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef REMOTING_CLIENT_OPENGL_GL_MATH_H_
-#define REMOTING_CLIENT_OPENGL_GL_MATH_H_
+#ifndef REMOTING_CLIENT_DISPLAY_GL_MATH_H_
+#define REMOTING_CLIENT_DISPLAY_GL_MATH_H_
 
 #include <array>
 #include <string>
@@ -43,4 +43,4 @@ std::string MatrixToString(const float* mat, int num_rows, int num_cols);
 
 }  // namespace remoting
 
-#endif  // REMOTING_CLIENT_OPENGL_GL_MATH_H_
+#endif  // REMOTING_CLIENT_DISPLAY_GL_MATH_H_