Add the ability to enable/disable GPU path renderers

Adds a bitfield to GrContextOptions that masks out path renderers.
Adds commandline flags support to set this bitfield in tools apps.
Removes GrGLInterfaceRemoveNVPR since we can now accomplish the same
thing in the context options.

BUG=skia:

Change-Id: Icf2a4df36374b3ba2f69ebf0db56e8aedd6cf65f
Reviewed-on: https://skia-review.googlesource.com/8786
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
diff --git a/bench/nanobench.cpp b/bench/nanobench.cpp
index e97e9a0..f73ae46 100644
--- a/bench/nanobench.cpp
+++ b/bench/nanobench.cpp
@@ -33,6 +33,7 @@
 #include "SkCodec.h"
 #include "SkCommonFlags.h"
 #include "SkCommonFlagsConfig.h"
+#include "SkCommonFlagsPathRenderer.h"
 #include "SkData.h"
 #include "SkGraphics.h"
 #include "SkLeanWindows.h"
@@ -128,6 +129,10 @@
 DEFINE_string(benchType,  "",
         "Apply usual --match rules to bench type: micro, recording, piping, playback, skcodec, etc.");
 
+#if SK_SUPPORT_GPU
+DEFINE_pathrenderer_flag;
+#endif
+
 static double now_ms() { return SkTime::GetNSecs() * 1e-6; }
 
 static SkString humanize(double ms) {
@@ -1106,6 +1111,7 @@
 
 #if SK_SUPPORT_GPU
     GrContextOptions grContextOpts;
+    grContextOpts.fGpuPathRenderers = CollectGpuPathRenderersFromFlags();
     gGrFactory.reset(new GrContextFactory(grContextOpts));
 #endif
 
diff --git a/dm/DM.cpp b/dm/DM.cpp
index c25076f..5e3185b 100644
--- a/dm/DM.cpp
+++ b/dm/DM.cpp
@@ -16,6 +16,7 @@
 #include "SkColorSpace.h"
 #include "SkCommonFlags.h"
 #include "SkCommonFlagsConfig.h"
+#include "SkCommonFlagsPathRenderer.h"
 #include "SkData.h"
 #include "SkFontMgr.h"
 #include "SkGraphics.h"
@@ -77,6 +78,10 @@
 
 DEFINE_string(mskps, "", "Directory to read mskps from, or a single mskp file.");
 
+#if SK_SUPPORT_GPU
+DEFINE_pathrenderer_flag;
+#endif
+
 using namespace DM;
 using sk_gpu_test::GrContextFactory;
 using sk_gpu_test::GLTestContext;
@@ -838,13 +843,13 @@
 #endif
 }
 
-static Sink* create_sink(const SkCommandLineConfig* config) {
+static Sink* create_sink(const GrContextOptions& grCtxOptions, const SkCommandLineConfig* config) {
 #if SK_SUPPORT_GPU
     if (gpu_supported()) {
         if (const SkCommandLineConfigGpu* gpuConfig = config->asConfigGpu()) {
             GrContextFactory::ContextType contextType = gpuConfig->getContextType();
             GrContextFactory::ContextOverrides contextOverrides = gpuConfig->getContextOverrides();
-            GrContextFactory testFactory;
+            GrContextFactory testFactory(grCtxOptions);
             if (!testFactory.get(contextType, contextOverrides)) {
                 info("WARNING: can not create GPU context for config '%s'. "
                      "GM tests will be skipped.\n", gpuConfig->getTag().c_str());
@@ -911,12 +916,12 @@
     return nullptr;
 }
 
-static bool gather_sinks() {
+static bool gather_sinks(const GrContextOptions& grCtxOptions) {
     SkCommandLineConfigArray configs;
     ParseConfigs(FLAGS_config, &configs);
     for (int i = 0; i < configs.count(); i++) {
         const SkCommandLineConfig& config = *configs[i];
-        Sink* sink = create_sink(&config);
+        Sink* sink = create_sink(grCtxOptions, &config);
         if (sink == nullptr) {
             info("Skipping config %s: Don't understand '%s'.\n", config.getTag().c_str(),
                  config.getTag().c_str());
@@ -1233,7 +1238,7 @@
     }
 }
 
-static void run_test(skiatest::Test test) {
+static void run_test(skiatest::Test test, const GrContextOptions& grCtxOptions) {
     struct : public skiatest::Reporter {
         void reportFailed(const skiatest::Failure& failure) override {
             fail(failure.toString());
@@ -1247,7 +1252,7 @@
 
     if (!FLAGS_dryRun && !is_blacklisted("_", "tests", "_", test.name)) {
         start("unit", "test", "", test.name);
-        GrContextFactory factory;
+        GrContextFactory factory(grCtxOptions);
         test.proc(&reporter, &factory);
     }
     done("unit", "test", "", test.name);
@@ -1307,6 +1312,11 @@
         gVLog = fopen(SkOSPath::Join(FLAGS_writePath[0], "verbose.log").c_str(), "w");
     }
 
+    GrContextOptions grCtxOptions;
+#if SK_SUPPORT_GPU
+    grCtxOptions.fGpuPathRenderers = CollectGpuPathRenderersFromFlags();
+#endif
+
     JsonWriter::DumpJson();  // It's handy for the bots to assume this is ~never missing.
     SkAutoGraphics ag;
     SkTaskGroup::Enabler enabled(FLAGS_threads);
@@ -1325,7 +1335,7 @@
     if (!gather_srcs()) {
         return 1;
     }
-    if (!gather_sinks()) {
+    if (!gather_sinks(grCtxOptions)) {
         return 1;
     }
     gather_tests();
@@ -1356,12 +1366,12 @@
         }
     }
     for (auto test : gParallelTests) {
-        parallel.add([test] { run_test(test); });
+        parallel.add([test, grCtxOptions] { run_test(test, grCtxOptions); });
     }
 
     // With the parallel work running, run serial tasks and tests here on main thread.
     for (auto task : serial) { Task::Run(task); }
-    for (auto test : gSerialTests) { run_test(test); }
+    for (auto test : gSerialTests) { run_test(test, grCtxOptions); }
 
     // Wait for any remaining parallel work to complete (including any spun off of serial tasks).
     parallel.wait();
diff --git a/example/SkiaSDLExample.cpp b/example/SkiaSDLExample.cpp
index 3aa42b3..abd198a 100644
--- a/example/SkiaSDLExample.cpp
+++ b/example/SkiaSDLExample.cpp
@@ -185,10 +185,6 @@
     // setup GrContext
     sk_sp<const GrGLInterface> interface(GrGLCreateNativeInterface());
 
-    // To use NVPR, comment this out
-    interface.reset(GrGLInterfaceRemoveNVPR(interface));
-    SkASSERT(interface);
-
     // setup contexts
     sk_sp<GrContext> grContext(GrContext::Create(kOpenGL_GrBackend,
                                                  (GrBackendContext)interface.get()));
diff --git a/gm/pathmaskcache.cpp b/gm/pathmaskcache.cpp
index 21397f0..5e3232b 100644
--- a/gm/pathmaskcache.cpp
+++ b/gm/pathmaskcache.cpp
@@ -104,7 +104,7 @@
     }
 
     void modifyGrContextOptions(GrContextOptions* options) override {
-        options->fForceSWPathMasks = true;
+        options->fGpuPathRenderers = GrContextOptions::GpuPathRenderers::kNone;
         options->fAllowPathMaskCaching = true;
     }
 
diff --git a/include/gpu/GrContextOptions.h b/include/gpu/GrContextOptions.h
index a2e4288..6c42ec6 100644
--- a/include/gpu/GrContextOptions.h
+++ b/include/gpu/GrContextOptions.h
@@ -9,6 +9,7 @@
 #define GrContextOptions_DEFINED
 
 #include "SkTypes.h"
+#include "GrTypes.h"
 
 struct GrContextOptions {
     GrContextOptions() {}
@@ -61,10 +62,6 @@
         Instanced rendering is still experimental at this point and disabled by default. */
     bool fEnableInstancedRendering = false;
 
-    /** Disables distance field rendering for paths. Distance field computation can be expensive
-        and yields no benefit if a path is not rendered multiple times with different transforms */
-    bool fDisableDistanceFieldPaths = false;
-
     /**
      * If true this allows path mask textures to be cached. This is only really useful if paths
      * are commonly rendered at the same scale and fractional translation.
@@ -72,13 +69,6 @@
     bool fAllowPathMaskCaching = false;
 
     /**
-     * Force all path draws to go through through the sw-rasterize-to-texture code path (assuming
-     * the path is not recognized as a simpler shape (e.g. a rrect). This is intended for testing
-     * purposes.
-     */
-    bool fForceSWPathMasks = false;
-
-    /**
      * If true, sRGB support will not be enabled unless sRGB decoding can be disabled (via an
      * extension). If mixed use of "legacy" mode and sRGB/color-correct mode is not required, this
      * can be set to false, which will significantly expand the number of devices that qualify for
@@ -91,6 +81,34 @@
      * textures from codec-backed images.
      */
     bool fDisableGpuYUVConversion = false;
+
+    /**
+     * If true, the caps will never report driver support for path rendering.
+     */
+    bool fSuppressPathRendering = false;
+
+    /**
+     * Allows the client to include or exclude specific GPU path renderers.
+     */
+    enum class GpuPathRenderers {
+        kNone              = 0, // Always use sofware masks.
+        kDashLine          = 1 << 0,
+        kStencilAndCover   = 1 << 1,
+        kMSAA              = 1 << 2,
+        kAAHairline        = 1 << 3,
+        kAAConvex          = 1 << 4,
+        kAALinearizing     = 1 << 5,
+        kPLS               = 1 << 6,
+        kDistanceField     = 1 << 7,
+        kTesselating       = 1 << 8,
+        kDefault           = 1 << 9,
+
+        kAll               = kDefault | (kDefault - 1)
+    };
+
+    GpuPathRenderers fGpuPathRenderers = GpuPathRenderers::kAll;
 };
 
+GR_MAKE_BITFIELD_CLASS_OPS(GrContextOptions::GpuPathRenderers)
+
 #endif
diff --git a/include/gpu/gl/GrGLInterface.h b/include/gpu/gl/GrGLInterface.h
index 3afa6be..cce1cb5 100644
--- a/include/gpu/gl/GrGLInterface.h
+++ b/include/gpu/gl/GrGLInterface.h
@@ -55,10 +55,6 @@
  */
 const SK_API GrGLInterface* GrGLCreateNullInterface(bool enableNVPR = false);
 
-/** Function that returns a new interface identical to "interface" but without support for
-    GL_NV_path_rendering. */
-const GrGLInterface* GrGLInterfaceRemoveNVPR(const GrGLInterface*);
-
 /** Function that returns a new interface identical to "interface" but with support for
     test version of GL_EXT_debug_marker. */
 const GrGLInterface* GrGLInterfaceAddTestDebugMarker(const GrGLInterface*,
diff --git a/samplecode/SampleApp.cpp b/samplecode/SampleApp.cpp
index 8b5e074..1aac794 100644
--- a/samplecode/SampleApp.cpp
+++ b/samplecode/SampleApp.cpp
@@ -14,6 +14,7 @@
 #include "SkCanvas.h"
 #include "SkColorSpace_XYZ.h"
 #include "SkCommandLineFlags.h"
+#include "SkCommonFlagsPathRenderer.h"
 #include "SkData.h"
 #include "SkDocument.h"
 #include "SkGraphics.h"
@@ -208,7 +209,7 @@
 #endif
     }
 
-    void setUpBackend(SampleWindow* win, int msaaSampleCount, bool deepColor) override {
+    void setUpBackend(SampleWindow* win, const BackendOptions& backendOptions) override {
         SkASSERT(kNone_BackEndType == fBackend);
 
         fBackend = kNone_BackEndType;
@@ -231,27 +232,27 @@
                 break;
         }
         AttachmentInfo attachmentInfo;
-        bool result = win->attach(fBackend, msaaSampleCount, deepColor, &attachmentInfo);
+        bool result = win->attach(fBackend, backendOptions.fMSAASampleCount,
+                                  backendOptions.fDeepColor, &attachmentInfo);
         if (!result) {
             SkDebugf("Failed to initialize GL");
             return;
         }
-        fMSAASampleCount = msaaSampleCount;
-        fDeepColor = deepColor;
+        fMSAASampleCount = backendOptions.fMSAASampleCount;
+        fDeepColor = backendOptions.fDeepColor;
         // Assume that we have at least 24-bit output, for backends that don't supply this data
         fActualColorBits = SkTMax(attachmentInfo.fColorBits, 24);
 
         SkASSERT(nullptr == fCurIntf);
-        sk_sp<const GrGLInterface> glInterface;
         switch (win->getDeviceType()) {
             case kRaster_DeviceType:    // fallthrough
             case kGPU_DeviceType:
                 // all these guys use the native interface
-                glInterface.reset(GrGLCreateNativeInterface());
+                fCurIntf = GrGLCreateNativeInterface();
                 break;
 #if SK_ANGLE
             case kANGLE_DeviceType:
-                glInterface.reset(sk_gpu_test::CreateANGLEGLInterface());
+                fCurIntf = sk_gpu_test::CreateANGLEGLInterface();
                 break;
 #endif // SK_ANGLE
             default:
@@ -259,12 +260,9 @@
                 break;
         }
 
-        // Currently SampleApp does not use NVPR. TODO: Provide an NVPR device type that is skipped
-        // when the driver doesn't support NVPR.
-        fCurIntf = GrGLInterfaceRemoveNVPR(glInterface.get());
-
         SkASSERT(nullptr == fCurContext);
-        fCurContext = GrContext::Create(kOpenGL_GrBackend, (GrBackendContext) fCurIntf);
+        fCurContext = GrContext::Create(kOpenGL_GrBackend, (GrBackendContext) fCurIntf,
+                                        backendOptions.fGrContextOptions);
 
         if (nullptr == fCurContext || nullptr == fCurIntf) {
             // We need some context and interface to see results
@@ -723,8 +721,6 @@
 }
 
 DEFINE_string(slide, "", "Start on this sample.");
-DEFINE_int32(msaa, 0, "Request multisampling with this count.");
-DEFINE_bool(deepColor, false, "Request deep color (10-bit/channel or more) display buffer.");
 DEFINE_string(pictureDir, "", "Read pictures from here.");
 DEFINE_string(picture, "", "Path to single picture.");
 DEFINE_string(svg, "", "Path to single SVG file.");
@@ -737,6 +733,11 @@
 #ifdef SAMPLE_PDF_FILE_VIEWER
 DEFINE_string(pdfPath, "", "Path to direcotry of pdf files.");
 #endif
+#if SK_SUPPORT_GPU
+DEFINE_pathrenderer_flag;
+DEFINE_int32(msaa, 0, "Request multisampling with this count.");
+DEFINE_bool(deepColor, false, "Request deep color (10-bit/channel or more) display buffer.");
+#endif
 
 #include "SkTaskGroup.h"
 
@@ -826,8 +827,11 @@
         }
     }
 
-    fMSAASampleCount = FLAGS_msaa;
-    fDeepColor = FLAGS_deepColor;
+#if SK_SUPPORT_GPU
+    fBackendOptions.fGrContextOptions.fGpuPathRenderers = CollectGpuPathRenderersFromFlags();
+    fBackendOptions.fMSAASampleCount = FLAGS_msaa;
+    fBackendOptions.fDeepColor = FLAGS_deepColor;
+#endif
     fColorConfigIndex = 0;
 
     if (FLAGS_list) {
@@ -996,7 +1000,7 @@
         devManager->ref();
         fDevManager = devManager;
     }
-    fDevManager->setUpBackend(this, fMSAASampleCount, fDeepColor);
+    fDevManager->setUpBackend(this, fBackendOptions);
 
     // If another constructor set our dimensions, ensure that our
     // onSizeChange gets called.
@@ -1916,7 +1920,7 @@
 
     fDevManager->tearDownBackend(this);
     fDeviceType = type;
-    fDevManager->setUpBackend(this, fMSAASampleCount, fDeepColor);
+    fDevManager->setUpBackend(this, fBackendOptions);
 
     this->updateTitle();
     this->inval(nullptr);
@@ -1926,7 +1930,7 @@
     this->setColorType(ct, std::move(cs));
 
     fDevManager->tearDownBackend(this);
-    fDevManager->setUpBackend(this, fMSAASampleCount, fDeepColor);
+    fDevManager->setUpBackend(this, fBackendOptions);
 
     this->updateTitle();
     this->inval(nullptr);
@@ -1953,7 +1957,7 @@
 void SampleWindow::toggleDistanceFieldFonts() {
     // reset backend
     fDevManager->tearDownBackend(this);
-    fDevManager->setUpBackend(this, fMSAASampleCount, fDeepColor);
+    fDevManager->setUpBackend(this, fBackendOptions);
 
     SkSurfaceProps props = this->getSurfaceProps();
     uint32_t flags = props.flags() ^ SkSurfaceProps::kUseDeviceIndependentFonts_Flag;
@@ -1966,7 +1970,7 @@
 void SampleWindow::setPixelGeometry(int pixelGeometryIndex) {
     // reset backend
     fDevManager->tearDownBackend(this);
-    fDevManager->setUpBackend(this, fMSAASampleCount, fDeepColor);
+    fDevManager->setUpBackend(this, fBackendOptions);
 
     const SkSurfaceProps& oldProps = this->getSurfaceProps();
     SkSurfaceProps newProps(oldProps.flags(), SkSurfaceProps::kLegacyFontHost_InitType);
diff --git a/samplecode/SampleApp.h b/samplecode/SampleApp.h
index c52541d..7b0dbf4 100644
--- a/samplecode/SampleApp.h
+++ b/samplecode/SampleApp.h
@@ -22,6 +22,10 @@
 
 #include "SkPipe.h"
 
+#if SK_SUPPORT_GPU
+#include "GrContextOptions.h"
+#endif
+
 class GrContext;
 class GrRenderTarget;
 
@@ -70,9 +74,15 @@
      */
     class DeviceManager : public SkRefCnt {
     public:
+        struct BackendOptions {
+#if SK_SUPPORT_GPU
+            GrContextOptions   fGrContextOptions;
+            int                fMSAASampleCount;
+            bool               fDeepColor;
+#endif
+        };
 
-
-        virtual void setUpBackend(SampleWindow* win, int msaaSampleCount, bool deepColor) = 0;
+        virtual void setUpBackend(SampleWindow* win, const BackendOptions&) = 0;
 
         virtual void tearDownBackend(SampleWindow* win) = 0;
 
@@ -219,8 +229,8 @@
     int fFilterQualityIndex;
     unsigned   fFlipAxis;
 
-    int fMSAASampleCount;
-    bool fDeepColor;
+    DeviceManager::BackendOptions fBackendOptions;
+
     int fColorConfigIndex;
 
     SkScalar fZoomCenterX, fZoomCenterY;
diff --git a/src/gpu/GrContext.cpp b/src/gpu/GrContext.cpp
index 8460702..4b1324e 100644
--- a/src/gpu/GrContext.cpp
+++ b/src/gpu/GrContext.cpp
@@ -99,9 +99,8 @@
     rtOpListOptions.fMaxOpCombineLookback = options.fMaxOpCombineLookback;
     rtOpListOptions.fMaxOpCombineLookahead = options.fMaxOpCombineLookahead;
     GrPathRendererChain::Options prcOptions;
-    prcOptions.fDisableDistanceFieldRenderer = options.fDisableDistanceFieldPaths;
     prcOptions.fAllowPathMaskCaching = options.fAllowPathMaskCaching;
-    prcOptions.fDisableAllPathRenderers = options.fForceSWPathMasks;
+    prcOptions.fGpuPathRenderers = options.fGpuPathRenderers;
     fDrawingManager.reset(new GrDrawingManager(this, rtOpListOptions, prcOptions,
                                                options.fImmediateMode, &fSingleOwner));
 
diff --git a/src/gpu/GrPathRendererChain.cpp b/src/gpu/GrPathRendererChain.cpp
index c0cac80..4b4ae26 100644
--- a/src/gpu/GrPathRendererChain.cpp
+++ b/src/gpu/GrPathRendererChain.cpp
@@ -26,44 +26,49 @@
 #include "ops/GrTessellatingPathRenderer.h"
 
 GrPathRendererChain::GrPathRendererChain(GrContext* context, const Options& options) {
-    if (!options.fDisableAllPathRenderers) {
-        const GrCaps& caps = *context->caps();
-        this->addPathRenderer(new GrDashLinePathRenderer)->unref();
-
-        if (GrPathRenderer* pr = GrStencilAndCoverPathRenderer::Create(context->resourceProvider(),
-                                                                       caps)) {
-            this->addPathRenderer(pr)->unref();
+    using GpuPathRenderers = GrContextOptions::GpuPathRenderers;
+    const GrCaps& caps = *context->caps();
+    if (options.fGpuPathRenderers & GpuPathRenderers::kDashLine) {
+        fChain.push_back(sk_make_sp<GrDashLinePathRenderer>());
+    }
+    if (options.fGpuPathRenderers & GpuPathRenderers::kStencilAndCover) {
+        sk_sp<GrPathRenderer> pr(
+            GrStencilAndCoverPathRenderer::Create(context->resourceProvider(), caps));
+        if (pr) {
+            fChain.push_back(std::move(pr));
         }
-    #ifndef SK_BUILD_FOR_ANDROID_FRAMEWORK
+    }
+#ifndef SK_BUILD_FOR_ANDROID_FRAMEWORK
+    if (options.fGpuPathRenderers & GpuPathRenderers::kMSAA) {
         if (caps.sampleShadingSupport()) {
-            this->addPathRenderer(new GrMSAAPathRenderer)->unref();
+            fChain.push_back(sk_make_sp<GrMSAAPathRenderer>());
         }
-    #endif
-        this->addPathRenderer(new GrAAHairLinePathRenderer)->unref();
-        this->addPathRenderer(new GrAAConvexPathRenderer)->unref();
-        this->addPathRenderer(new GrAALinearizingConvexPathRenderer)->unref();
+    }
+#endif
+    if (options.fGpuPathRenderers & GpuPathRenderers::kAAHairline) {
+        fChain.push_back(sk_make_sp<GrAAHairLinePathRenderer>());
+    }
+    if (options.fGpuPathRenderers & GpuPathRenderers::kAAConvex) {
+        fChain.push_back(sk_make_sp<GrAAConvexPathRenderer>());
+    }
+    if (options.fGpuPathRenderers & GpuPathRenderers::kAALinearizing) {
+        fChain.push_back(sk_make_sp<GrAALinearizingConvexPathRenderer>());
+    }
+    if (options.fGpuPathRenderers & GpuPathRenderers::kPLS) {
         if (caps.shaderCaps()->plsPathRenderingSupport()) {
-            this->addPathRenderer(new GrPLSPathRenderer)->unref();
+            fChain.push_back(sk_make_sp<GrPLSPathRenderer>());
         }
-        if (!options.fDisableDistanceFieldRenderer) {
-            this->addPathRenderer(new GrAADistanceFieldPathRenderer)->unref();
-        }
-        this->addPathRenderer(new GrTessellatingPathRenderer)->unref();
-        this->addPathRenderer(new GrDefaultPathRenderer(caps.twoSidedStencilSupport(),
-                                                        caps.stencilWrapOpsSupport()))->unref();
     }
-}
-
-GrPathRendererChain::~GrPathRendererChain() {
-    for (int i = 0; i < fChain.count(); ++i) {
-        fChain[i]->unref();
+    if (options.fGpuPathRenderers & GpuPathRenderers::kDistanceField) {
+        fChain.push_back(sk_make_sp<GrAADistanceFieldPathRenderer>());
     }
-}
-
-GrPathRenderer* GrPathRendererChain::addPathRenderer(GrPathRenderer* pr) {
-    fChain.push_back() = pr;
-    pr->ref();
-    return pr;
+    if (options.fGpuPathRenderers & GpuPathRenderers::kTesselating) {
+        fChain.push_back(sk_make_sp<GrTessellatingPathRenderer>());
+    }
+    if (options.fGpuPathRenderers & GpuPathRenderers::kDefault) {
+        fChain.push_back(sk_make_sp<GrDefaultPathRenderer>(caps.twoSidedStencilSupport(),
+                                                           caps.stencilWrapOpsSupport()));
+    }
 }
 
 GrPathRenderer* GrPathRendererChain::getPathRenderer(
@@ -99,7 +104,7 @@
                     *stencilSupport = support;
                 }
             }
-            return fChain[i];
+            return fChain[i].get();
         }
     }
     return nullptr;
diff --git a/src/gpu/GrPathRendererChain.h b/src/gpu/GrPathRendererChain.h
index 9a1a8fe..c0a0ee3 100644
--- a/src/gpu/GrPathRendererChain.h
+++ b/src/gpu/GrPathRendererChain.h
@@ -10,6 +10,7 @@
 
 #include "GrPathRenderer.h"
 
+#include "GrContextOptions.h"
 #include "SkTypes.h"
 #include "SkTArray.h"
 
@@ -24,14 +25,12 @@
 class GrPathRendererChain : public SkNoncopyable {
 public:
     struct Options {
-        bool fDisableDistanceFieldRenderer = false;
+        using GpuPathRenderers = GrContextOptions::GpuPathRenderers;
         bool fAllowPathMaskCaching = false;
-        bool fDisableAllPathRenderers = false;
+        GpuPathRenderers fGpuPathRenderers = GpuPathRenderers::kAll;
     };
     GrPathRendererChain(GrContext* context, const Options&);
 
-    ~GrPathRendererChain();
-
     /** Documents how the caller plans to use a GrPathRenderer to draw a path. It affects the PR
         returned by getPathRenderer */
     enum class DrawType {
@@ -49,13 +48,10 @@
                                     GrPathRenderer::StencilSupport* stencilSupport);
 
 private:
-    // takes a ref and unrefs in destructor
-    GrPathRenderer* addPathRenderer(GrPathRenderer* pr);
-
     enum {
         kPreAllocCount = 8,
     };
-    SkSTArray<kPreAllocCount, GrPathRenderer*, true>    fChain;
+    SkSTArray<kPreAllocCount, sk_sp<GrPathRenderer>>    fChain;
 };
 
 #endif
diff --git a/src/gpu/gl/GrGLCaps.cpp b/src/gpu/gl/GrGLCaps.cpp
index 4c25221..370fb07 100644
--- a/src/gpu/gl/GrGLCaps.cpp
+++ b/src/gpu/gl/GrGLCaps.cpp
@@ -258,7 +258,9 @@
     this->initGLSL(ctxInfo);
     GrShaderCaps* shaderCaps = fShaderCaps.get();
 
-    shaderCaps->fPathRenderingSupport = this->hasPathRenderingSupport(ctxInfo, gli);
+    if (!contextOptions.fSuppressPathRendering) {
+        shaderCaps->fPathRenderingSupport = this->hasPathRenderingSupport(ctxInfo, gli);
+    }
 
     // For now these two are equivalent but we could have dst read in shader via some other method.
     // Before setting this, initGLSL() must have been called.
diff --git a/src/gpu/gl/GrGLInterface.cpp b/src/gpu/gl/GrGLInterface.cpp
index 45d84ad..3714dcb 100644
--- a/src/gpu/gl/GrGLInterface.cpp
+++ b/src/gpu/gl/GrGLInterface.cpp
@@ -29,37 +29,6 @@
     return newInterface;
 }
 
-const GrGLInterface* GrGLInterfaceRemoveNVPR(const GrGLInterface* interface) {
-    GrGLInterface* newInterface = GrGLInterface::NewClone(interface);
-
-    newInterface->fExtensions.remove("GL_NV_path_rendering");
-    newInterface->fExtensions.remove("GL_CHROMIUM_path_rendering");
-    newInterface->fFunctions.fMatrixLoadf = nullptr;
-    newInterface->fFunctions.fMatrixLoadIdentity = nullptr;
-    newInterface->fFunctions.fPathCommands = nullptr;
-    newInterface->fFunctions.fPathParameteri = nullptr;
-    newInterface->fFunctions.fPathParameterf = nullptr;
-    newInterface->fFunctions.fGenPaths = nullptr;
-    newInterface->fFunctions.fDeletePaths = nullptr;
-    newInterface->fFunctions.fIsPath = nullptr;
-    newInterface->fFunctions.fPathStencilFunc = nullptr;
-    newInterface->fFunctions.fStencilFillPath = nullptr;
-    newInterface->fFunctions.fStencilStrokePath = nullptr;
-    newInterface->fFunctions.fStencilFillPathInstanced = nullptr;
-    newInterface->fFunctions.fStencilStrokePathInstanced = nullptr;
-    newInterface->fFunctions.fCoverFillPath = nullptr;
-    newInterface->fFunctions.fCoverStrokePath = nullptr;
-    newInterface->fFunctions.fCoverFillPathInstanced = nullptr;
-    newInterface->fFunctions.fCoverStrokePathInstanced = nullptr;
-    newInterface->fFunctions.fStencilThenCoverFillPath = nullptr;
-    newInterface->fFunctions.fStencilThenCoverStrokePath = nullptr;
-    newInterface->fFunctions.fStencilThenCoverFillPathInstanced = nullptr;
-    newInterface->fFunctions.fStencilThenCoverStrokePathInstanced = nullptr;
-    newInterface->fFunctions.fProgramPathFragmentInputGen = nullptr;
-    newInterface->fFunctions.fBindFragmentInputLocation = nullptr;
-    return newInterface;
-}
-
 GrGLInterface::GrGLInterface() {
     fStandard = kNone_GrGLStandard;
 }
diff --git a/tools/flags/SkCommonFlagsPathRenderer.h b/tools/flags/SkCommonFlagsPathRenderer.h
new file mode 100644
index 0000000..d3b80f5
--- /dev/null
+++ b/tools/flags/SkCommonFlagsPathRenderer.h
@@ -0,0 +1,74 @@
+/*
+ * Copyright 2017 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SK_COMMON_FLAGS_PATH_RENDERER_H
+#define SK_COMMON_FLAGS_PATH_RENDERER_H
+
+#if SK_SUPPORT_GPU
+
+#include "GrContextFactory.h"
+#include "SkCommandLineFlags.h"
+#include "SkTypes.h"
+
+DECLARE_string(pr);
+
+#define DEFINE_pathrenderer_flag \
+    DEFINE_string(pr, "all", \
+                  "Set of enabled gpu path renderers. Defined as a list of: " \
+                    "[[~]all [~]dashline [~]nvpr [~]msaa [~]aahairline [~]aaconvex " \
+                    "[~]aalinearizing [~]pls [~]sdf [~]tess [~]grdefault]")
+
+inline GrContextOptions::GpuPathRenderers get_named_pathrenderers_flags(const char* name) {
+    using GpuPathRenderers = GrContextOptions::GpuPathRenderers;
+    if (!strcmp(name, "all")) {
+        return GpuPathRenderers::kAll;
+    } else if (!strcmp(name, "dashline")) {
+        return GpuPathRenderers::kDashLine;
+    } else if (!strcmp(name, "nvpr")) {
+        return GpuPathRenderers::kStencilAndCover;
+    } else if (!strcmp(name, "msaa")) {
+        return GpuPathRenderers::kMSAA;
+    } else if (!strcmp(name, "aahairline")) {
+        return GpuPathRenderers::kAAHairline;
+    } else if (!strcmp(name, "aaconvex")) {
+        return GpuPathRenderers::kAAConvex;
+    } else if (!strcmp(name, "aalinearizing")) {
+        return GpuPathRenderers::kAALinearizing;
+    } else if (!strcmp(name, "pls")) {
+        return GpuPathRenderers::kPLS;
+    } else if (!strcmp(name, "sdf")) {
+        return GpuPathRenderers::kDistanceField;
+    } else if (!strcmp(name, "tess")) {
+        return GpuPathRenderers::kTesselating;
+    } else if (!strcmp(name, "grdefault")) {
+        return GpuPathRenderers::kDefault;
+    }
+    SK_ABORT(SkStringPrintf("error: unknown named path renderer \"%s\"\n", name).c_str());
+    return GpuPathRenderers::kNone;
+}
+
+inline GrContextOptions::GpuPathRenderers CollectGpuPathRenderersFromFlags() {
+    using GpuPathRenderers = GrContextOptions::GpuPathRenderers;
+    if (FLAGS_pr.isEmpty()) {
+        return GpuPathRenderers::kAll;
+    }
+    GpuPathRenderers gpuPathRenderers = '~' == FLAGS_pr[0][0] ?
+                                        GpuPathRenderers::kAll : GpuPathRenderers::kNone;
+    for (int i = 0; i < FLAGS_pr.count(); ++i) {
+        const char* name = FLAGS_pr[i];
+        if (name[0] == '~') {
+            gpuPathRenderers &= ~get_named_pathrenderers_flags(&name[1]);
+        } else {
+            gpuPathRenderers |= get_named_pathrenderers_flags(name);
+        }
+    }
+    return gpuPathRenderers;
+}
+
+#endif // SK_SUPPORT_GPU
+
+#endif
diff --git a/tools/gpu/GrContextFactory.cpp b/tools/gpu/GrContextFactory.cpp
index 965e646..637c569 100644
--- a/tools/gpu/GrContextFactory.cpp
+++ b/tools/gpu/GrContextFactory.cpp
@@ -196,12 +196,6 @@
             }
             testCtx.reset(glCtx);
             glInterface.reset(SkRef(glCtx->gl()));
-            if (ContextOverrides::kDisableNVPR & overrides) {
-                glInterface.reset(GrGLInterfaceRemoveNVPR(glInterface.get()));
-                if (!glInterface) {
-                    return ContextInfo();
-                }
-            }
             backendContext = reinterpret_cast<GrBackendContext>(glInterface.get());
             break;
         }
@@ -238,6 +232,9 @@
     testCtx->makeCurrent();
     SkASSERT(testCtx && testCtx->backend() == backend);
     GrContextOptions grOptions = fGlobalOptions;
+    if (ContextOverrides::kDisableNVPR & overrides) {
+        grOptions.fSuppressPathRendering = true;
+    }
     if (ContextOverrides::kUseInstanced & overrides) {
         grOptions.fEnableInstancedRendering = true;
     }
diff --git a/tools/skpbench/skpbench.cpp b/tools/skpbench/skpbench.cpp
index 3887c5e..569c204 100644
--- a/tools/skpbench/skpbench.cpp
+++ b/tools/skpbench/skpbench.cpp
@@ -8,6 +8,7 @@
 #include "GpuTimer.h"
 #include "GrContextFactory.h"
 #include "SkCanvas.h"
+#include "SkCommonFlagsPathRenderer.h"
 #include "SkOSFile.h"
 #include "SkOSPath.h"
 #include "SkPerlinNoiseShader.h"
@@ -46,6 +47,7 @@
 DEFINE_string(png, "", "if set, save a .png proof to disk at this file location");
 DEFINE_int32(verbosity, 4, "level of verbosity (0=none to 5=debug)");
 DEFINE_bool(suppressHeader, false, "don't print a header row before the results");
+DEFINE_pathrenderer_flag;
 
 static const char* header =
 "   accum    median       max       min   stddev  samples  sample_ms  clock  metric  config    bench";
@@ -271,7 +273,9 @@
     }
 
     // Create a context.
-    sk_gpu_test::GrContextFactory factory;
+    GrContextOptions ctxOptions;
+    ctxOptions.fGpuPathRenderers = CollectGpuPathRenderersFromFlags();
+    sk_gpu_test::GrContextFactory factory(ctxOptions);
     sk_gpu_test::ContextInfo ctxInfo =
         factory.getContextInfo(config->getContextType(), config->getContextOverrides());
     GrContext* ctx = ctxInfo.grContext();
diff --git a/tools/viewer/Viewer.cpp b/tools/viewer/Viewer.cpp
index 57185d2..092910a 100644
--- a/tools/viewer/Viewer.cpp
+++ b/tools/viewer/Viewer.cpp
@@ -16,6 +16,7 @@
 #include "SkATrace.h"
 #include "SkCanvas.h"
 #include "SkCommandLineFlags.h"
+#include "SkCommonFlagsPathRenderer.h"
 #include "SkDashPathEffect.h"
 #include "SkGraphics.h"
 #include "SkImagePriv.h"
@@ -134,6 +135,8 @@
 
 static DEFINE_bool(atrace, false, "Enable support for using ATrace. ATrace is only supported on Android.");
 
+DEFINE_pathrenderer_flag;
+
 const char *kBackendTypeStrings[sk_app::Window::kBackendTypeCount] = {
     " [OpenGL]",
 #ifdef SK_VULKAN
diff --git a/tools/viewer/sk_app/GLWindowContext.cpp b/tools/viewer/sk_app/GLWindowContext.cpp
index 501f272..fac0c32 100644
--- a/tools/viewer/sk_app/GLWindowContext.cpp
+++ b/tools/viewer/sk_app/GLWindowContext.cpp
@@ -7,6 +7,7 @@
  */
 
 #include "GrContext.h"
+#include "SkCommonFlagsPathRenderer.h"
 #include "SkSurface.h"
 #include "GLWindowContext.h"
 
@@ -30,12 +31,13 @@
 
 void GLWindowContext::initializeContext() {
     this->onInitializeContext();
-    sk_sp<const GrGLInterface> glInterface;
-    glInterface.reset(GrGLCreateNativeInterface());
-    fBackendContext.reset(GrGLInterfaceRemoveNVPR(glInterface.get()));
-
     SkASSERT(nullptr == fContext);
-    fContext = GrContext::Create(kOpenGL_GrBackend, (GrBackendContext)fBackendContext.get());
+
+    GrContextOptions ctxOptions;
+    ctxOptions.fGpuPathRenderers = CollectGpuPathRenderersFromFlags();
+    fBackendContext.reset(GrGLCreateNativeInterface());
+    fContext = GrContext::Create(kOpenGL_GrBackend, (GrBackendContext)fBackendContext.get(),
+                                 ctxOptions);
 
     // We may not have real sRGB support (ANGLE, in particular), so check for
     // that, and fall back to L32:
diff --git a/tools/viewer/sk_app/VulkanWindowContext.cpp b/tools/viewer/sk_app/VulkanWindowContext.cpp
index b4e6676..65273b0 100644
--- a/tools/viewer/sk_app/VulkanWindowContext.cpp
+++ b/tools/viewer/sk_app/VulkanWindowContext.cpp
@@ -8,6 +8,7 @@
 
 #include "GrContext.h"
 #include "GrRenderTarget.h"
+#include "SkCommonFlagsPathRenderer.h"
 #include "SkAutoMalloc.h"
 #include "SkSurface.h"
 #include "VulkanWindowContext.h"
@@ -61,7 +62,10 @@
     GET_DEV_PROC(AcquireNextImageKHR);
     GET_DEV_PROC(QueuePresentKHR);
 
-    fContext = GrContext::Create(kVulkan_GrBackend, (GrBackendContext) fBackendContext.get());
+    GrContextOptions ctxOptions;
+    ctxOptions.fGpuPathRenderers = CollectGpuPathRenderersFromFlags();
+    fContext = GrContext::Create(kVulkan_GrBackend, (GrBackendContext) fBackendContext.get(),
+                                 ctxOptions);
 
     fSurface = createVkSurface(instance);
     if (VK_NULL_HANDLE == fSurface) {