Fix Ganesh perspective projection bug

src/gpu/gl/GrGLProgram.h

Index: src/gpu/gl/GrGLProgram.h
diff --git a/src/gpu/gl/GrGLProgram.h b/src/gpu/gl/GrGLProgram.h
index 7b10c147b4f33c8d68e1f0ea6eb37f9aa6987283..9381a6c204bf43d9b057e0f4d5b3400cf41f2f82 100644
--- a/src/gpu/gl/GrGLProgram.h
+++ b/src/gpu/gl/GrGLProgram.h
@@ -72,7 +72,7 @@ public:
          * coords. Assuming the transformed position, pos, is a homogeneous vec3, the vec, v, is
          * applied as such:
          * pos.x = dot(v.xy, pos.xz)
-         * pos.y = dot(v.zq, pos.yz)
+         * pos.y = dot(v.zw, pos.yz)
          */
         void getRTAdjustmentVec(GrGLfloat* destVec) {
             destVec[0] = 2.f / fRenderTargetSize.fWidth;