Revert of Turned on SkSL->GLSL compiler

src/gpu/glsl/GrGLSLFragmentShaderBuilder.cpp

Index: src/gpu/glsl/GrGLSLFragmentShaderBuilder.cpp
diff --git a/src/gpu/glsl/GrGLSLFragmentShaderBuilder.cpp b/src/gpu/glsl/GrGLSLFragmentShaderBuilder.cpp
index f1c655c58c386c53a4d2f8eed2d8a2a24c0dcfd1..7763f86e42957b664c027a2931a0f8d3da44e807 100644
--- a/src/gpu/glsl/GrGLSLFragmentShaderBuilder.cpp
+++ b/src/gpu/glsl/GrGLSLFragmentShaderBuilder.cpp
@@ -321,7 +321,7 @@
 }
 
 const char* GrGLSLFragmentShaderBuilder::getPrimaryColorOutputName() const {
-    return fHasCustomColorOutput ? DeclaredColorOutputName() : "sk_FragColor";
+    return fHasCustomColorOutput ? DeclaredColorOutputName() : "gl_FragColor";
 }
 
 void GrGLSLFragmentBuilder::declAppendf(const char* fmt, ...) {