Add factory class for generating various flavors of GrTextContext.

src/gpu/GrBitmapTextContext.cpp

Index: src/gpu/GrBitmapTextContext.cpp
diff --git a/src/gpu/GrBitmapTextContext.cpp b/src/gpu/GrBitmapTextContext.cpp
index a43c4a28746be3551b07d9dd9e68ca97df4293ed..6e33d90d07fb53f0af25139664a20fb7dbffbf87 100755
--- a/src/gpu/GrBitmapTextContext.cpp
+++ b/src/gpu/GrBitmapTextContext.cpp
@@ -24,12 +24,10 @@ SK_CONF_DECLARE(bool, c_DumpFontCache, "gpu.dumpFontCache", false,
                 "Dump the contents of the font cache before every purge.");
 
 GrBitmapTextContext::GrBitmapTextContext(GrContext* context, const GrPaint& paint,
-                                         SkColor color) :
-                                         GrTextContext(context, paint) {
+                                         const SkPaint& skPaint) :
+                                         GrTextContext(context, paint, skPaint) {
     fAutoMatrix.setIdentity(fContext, &fPaint);
 
-    fSkPaintColor = color;
-
     fStrike = NULL;
 
     fCurrTexture = NULL;
@@ -83,11 +81,11 @@ void GrBitmapTextContext::flushGlyphs() {
             // alpha. Instead we feed in a non-premultiplied color, and multiply its alpha by
             // the mask texture color. The end result is that we get
             //            mask*paintAlpha*paintColor + (1-mask*paintAlpha)*dstColor
-            int a = SkColorGetA(fSkPaintColor);
+            int a = SkColorGetA(fSkPaint.getColor());
             // paintAlpha
             drawState->setColor(SkColorSetARGB(a, a, a, a));
             // paintColor
-            drawState->setBlendConstant(skcolor_to_grcolor_nopremultiply(fSkPaintColor));
+            drawState->setBlendConstant(skcolor_to_grcolor_nopremultiply(fSkPaint.getColor()));
             drawState->setBlendFunc(kConstC_GrBlendCoeff, kISC_GrBlendCoeff);
         } else {
             // set back to normal in case we took LCD path previously.