Add factory class for generating various flavors of GrTextContext.

src/gpu/GrTextContext.cpp

Index: src/gpu/GrTextContext.cpp
diff --git a/src/gpu/GrTextContext.cpp b/src/gpu/GrTextContext.cpp
index 9e9162878dff4e92a0054a3432d40d20fb697afe..77e98d2fd5fa30263707f34cf749f4099ba163d7 100644
--- a/src/gpu/GrTextContext.cpp
+++ b/src/gpu/GrTextContext.cpp
@@ -8,7 +8,8 @@
 
 #include "GrTextContext.h"
 
-GrTextContext::GrTextContext(GrContext* context, const GrPaint& paint) : fPaint(paint) {
+GrTextContext::GrTextContext(GrContext* context, const GrPaint& paint,
+                             const SkPaint& skPaint) : fPaint(paint), fSkPaint(skPaint) {
     fContext = context;
 
     const GrClipData* clipData = context->getClip();