Add GrContextOptions flag to disable distance field path renderer.

src/gpu/GrDrawingManager.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrDrawingManager.h"
 
 #include "GrContext.h"
@@ skipping 179 matching lines @@
  * the provided target.
  * Due to its expense, the software path renderer has split out so it can
  * can be individually allowed/disallowed via the "allowSW" boolean.
  */
 GrPathRenderer* GrDrawingManager::getPathRenderer(const GrPathRenderer::CanDrawPathArgs& args,
                                                   bool allowSW,
                                                   GrPathRendererChain::DrawType drawType,
                                                   GrPathRenderer::StencilSupport* stencilSupport) {
 
     if (!fPathRendererChain) {
-        fPathRendererChain = new GrPathRendererChain(fContext);
+        fPathRendererChain = new GrPathRendererChain(fContext, fOptionsForPathRendererChain);
     }
 
     GrPathRenderer* pr = fPathRendererChain->getPathRenderer(args, drawType, stencilSupport);
     if (!pr && allowSW) {
         if (!fSoftwarePathRenderer) {
             fSoftwarePathRenderer = new GrSoftwarePathRenderer(fContext->textureProvider());
         }
         pr = fSoftwarePathRenderer;
     }
 
@@ skipping 28 matching lines @@
                                                         std::move(colorSpace), surfaceProps,
                                                         fContext->getAuditTrail(), fSingleOwner));
         }
     }
 
     return sk_sp<GrDrawContext>(new GrDrawContext(fContext, this, std::move(rt),
                                                   std::move(colorSpace), surfaceProps,
                                                   fContext->getAuditTrail(),
                                                   fSingleOwner));
 }