Enable use of distance fields via SkPaint flag.

Now that distance field generation is fast enough to make it practical, this makes distances field fonts easily available to anyone who wants to try them out (i.e Chromium).

BUG=skia:2173
R=reed@google.com, bsalomon@google.com

Author: jvanverth@google.com

Review URL: https://codereview.chromium.org/193163003

git-svn-id: http://skia.googlecode.com/svn/trunk@13741 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/GrDistanceFieldTextContext.cpp b/src/gpu/GrDistanceFieldTextContext.cpp
index e372b6c..0450382 100755
--- a/src/gpu/GrDistanceFieldTextContext.cpp
+++ b/src/gpu/GrDistanceFieldTextContext.cpp
@@ -45,7 +45,8 @@
 }
 
 bool GrDistanceFieldTextContext::canDraw(const SkPaint& paint) {
-    return !paint.getRasterizer() && !paint.getMaskFilter() &&
+    return paint.isDistanceFieldTextTEMP() &&
+           !paint.getRasterizer() && !paint.getMaskFilter() &&
            paint.getStyle() == SkPaint::kFill_Style &&
            fContext->getTextTarget()->caps()->shaderDerivativeSupport() &&
            !SkDraw::ShouldDrawTextAsPaths(paint, fContext->getMatrix());