Add GrContextOptions flag to disable distance field path renderer.

src/gpu/GrContext.cpp

Index: src/gpu/GrContext.cpp
diff --git a/src/gpu/GrContext.cpp b/src/gpu/GrContext.cpp
index 47fb32312f42684ca389083851ec53c96f71349b..fbb59a3e9a678823302dfbc1dca08b8c088e0b1b 100644
--- a/src/gpu/GrContext.cpp
+++ b/src/gpu/GrContext.cpp
@@ -95,7 +95,9 @@ void GrContext::initCommon(const GrContextOptions& options) {
     dtOptions.fDrawBatchBounds = options.fDrawBatchBounds;
     dtOptions.fMaxBatchLookback = options.fMaxBatchLookback;
     dtOptions.fMaxBatchLookahead = options.fMaxBatchLookahead;
-    fDrawingManager.reset(new GrDrawingManager(this, dtOptions, options.fImmediateMode,
+    GrPathRendererChain::Options prcOptions;
+    prcOptions.fDisableDistanceFieldRenderer = options.fDisableDistanceFieldPaths;
+    fDrawingManager.reset(new GrDrawingManager(this, dtOptions, prcOptions, options.fImmediateMode,
                                                &fSingleOwner));
 
     // GrBatchFontCache will eventually replace GrFontCache