move all code generation under genProgram() in GrGLShaderBuilder. [email protected], [email protected] Author: [email protected] Review URL: https://codereview.chromium.org/306063002 git-svn-id: http://skia.googlecode.com/svn/trunk/src@14996 2bbb7eff-a529-9590-31e7-b0007b416f81