Renamed gles_book_examples to gles2_book to make it shorter and more correct....

third_party/gles_book_examples/Chapter_13/ProceduralTextures/checker.fs

Index: third_party/gles_book_examples/Chapter_13/ProceduralTextures/checker.fs
===================================================================
--- third_party/gles_book_examples/Chapter_13/ProceduralTextures/checker.fs	(revision 35873)
+++ third_party/gles_book_examples/Chapter_13/ProceduralTextures/checker.fs	(working copy)
@@ -1,21 +0,0 @@
-#ifdef GL_ES
-precision highp float;
-#endif
-
-uniform int     frequency;
-uniform vec4    color0;
-uniform vec4    color1;
-
-varying vec2    v_st;
-
-void
-main()
-{
-    float   s, t, delta;
-    
-    s = mod(floor(v_st.x * float(frequency * 2)), 2.0);
-    t = mod(floor(v_st.y * float(frequency * 2)), 2.0);    
-    delta = abs(s - t);
-    
-    gl_FragColor = mix(color1, color0, delta);
-}