[Chromoting] Implement GlRenderer

remoting/client/gl_math.h

Index: remoting/client/gl_math.h
diff --git a/remoting/client/gl_math.h b/remoting/client/gl_math.h
index 3ea6731f82db464c7334338ca036d8a7f4b6acd0..54b73131cdf89f520e20fc085cf040ede8395989 100644
--- a/remoting/client/gl_math.h
+++ b/remoting/client/gl_math.h
@@ -15,13 +15,15 @@ namespace remoting {
 // See GlCanvas::SetNormalizedTransformation for definition of the
 // transformation matrix.
 //
-// Converts a pixel based transformation matrix to a texture coordinates based
-// transformation matrix.
-// 3 by 3 transformation matrix, [ m0, m1, m2, m3, m4, m5, m6, m7, m8 ].
+// Converts a pixel based transformation matrix to a **transposed** texture
+// coordinates based transformation matrix.
+// 3 by 3 transformation matrix, [ m0, 0, m2, 0, m4, m5, 0, 0, m8 ].
+//
+// | m0,  0, m2, |   | x |
+// |  0, m4, m5, | * | y |
+// |  0,  0, m8  |   | 1 |
 //
-// | m0, m1, m2, |   | x |
-// | m3, m4, m5, | * | y |
-// | m6, m7, m8  |   | 1 |
+// m1, m3, m6, m7 all must be zero.
 void NormalizeTransformationMatrix(int view_width,
                                    int view_height,
                                    int canvas_width,