Pull out shader-specific caps into GrShaderCaps and GrGLSLCaps

src/gpu/GrAtlasTextContext.cpp

Index: src/gpu/GrAtlasTextContext.cpp
diff --git a/src/gpu/GrAtlasTextContext.cpp b/src/gpu/GrAtlasTextContext.cpp
index dee3be7635a4d0acb69ea504317c113572c15266..f1906c3f72b6390be453c436fe598f43a589d70e 100644
--- a/src/gpu/GrAtlasTextContext.cpp
+++ b/src/gpu/GrAtlasTextContext.cpp
@@ -447,7 +447,7 @@ inline bool GrAtlasTextContext::canDrawAsDistanceFields(const SkPaint& skPaint,
     // rasterizers and mask filters modify alpha, which doesn't
     // translate well to distance
     if (skPaint.getRasterizer() || skPaint.getMaskFilter() ||
-        !fContext->getTextTarget()->caps()->shaderDerivativeSupport()) {
+        !fContext->getTextTarget()->caps()->shaderCaps()->shaderDerivativeSupport()) {
         return false;
     }