Improve GrPathRendererChain heuristics

Changes GrPathRenderer::canDrawPath to return a 'CanDrawPath' enum,
which contains a new kAsBackup value that means "I'm better than SW,
but give the path renderers below me a chance first."

Bug: skia:
Change-Id: I45aac5462ca1bc0bc839eb1c315db9493901a07e
Reviewed-on: https://skia-review.googlesource.com/42222
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>

25 files changed, 154 insertions, 94 deletions

diff --git a/src/gpu/GrDrawingManager.cpp b/src/gpu/GrDrawingManager.cpp
index 31da84e7e6..bbcd8a85d9 100644
--- a/src/gpu/GrDrawingManager.cpp
+++ b/src/gpu/GrDrawingManager.cpp
@@ -312,7 +312,7 @@ GrPathRenderer* GrDrawingManager::getPathRenderer(const GrPathRenderer::CanDrawP
                     new GrSoftwarePathRenderer(fContext->resourceProvider(),
                                                fOptionsForPathRendererChain.fAllowPathMaskCaching);
         }
-        if (fSoftwarePathRenderer->canDrawPath(args)) {
+        if (GrPathRenderer::CanDrawPath::kNo != fSoftwarePathRenderer->canDrawPath(args)) {
             pr = fSoftwarePathRenderer;
         }
     }
diff --git a/src/gpu/GrPathRenderer.h b/src/gpu/GrPathRenderer.h
index a3cf8c6151..cf0ef6effc 100644
--- a/src/gpu/GrPathRenderer.h
+++ b/src/gpu/GrPathRenderer.h
@@ -67,6 +67,12 @@ public:
         return this->onGetStencilSupport(shape);
     }
 
+    enum class CanDrawPath {
+        kNo,
+        kAsBackup, // i.e. This renderer is better than SW fallback if no others can draw the path.
+        kYes
+    };
+
     /** Args to canDrawPath()
      *
      * fCaps             The context caps
@@ -94,13 +100,11 @@ public:
     };
 
     /**
-     * Returns true if this path renderer is able to render the path. Returning false allows the
-     * caller to fallback to another path renderer This function is called when searching for a path
-     * renderer capable of rendering a path.
-     *
-     * @return  true if the path can be drawn by this object, false otherwise.
+     * Returns how well this path renderer is able to render the given path. Returning kNo or
+     * kAsBackup allows the caller to keep searching for a better path renderer. This function is
+     * called when searching for the best path renderer to draw a path.
      */
-    bool canDrawPath(const CanDrawPathArgs& args) const {
+    CanDrawPath canDrawPath(const CanDrawPathArgs& args) const {
         SkDEBUGCODE(args.validate();)
         return this->onCanDrawPath(args);
     }
@@ -158,7 +162,7 @@ public:
                    GrFSAAType::kUnifiedMSAA != args.fRenderTargetContext->fsaaType()));
         SkASSERT(!(canArgs.fAAType == GrAAType::kMixedSamples &&
                    GrFSAAType::kMixedSamples != args.fRenderTargetContext->fsaaType()));
-        SkASSERT(this->canDrawPath(canArgs));
+        SkASSERT(CanDrawPath::kNo != this->canDrawPath(canArgs));
         if (!args.fUserStencilSettings->isUnused()) {
             SkPath path;
             args.fShape->asPath(&path);
@@ -253,7 +257,7 @@ private:
     /**
      * Subclass implementation of canDrawPath()
      */
-    virtual bool onCanDrawPath(const CanDrawPathArgs& args) const = 0;
+    virtual CanDrawPath onCanDrawPath(const CanDrawPathArgs& args) const = 0;
 
     /**
      * Subclass implementation of stencilPath(). Subclass must override iff it ever returns
diff --git a/src/gpu/GrPathRendererChain.cpp b/src/gpu/GrPathRendererChain.cpp
index 354d086a22..4a39f256fe 100644
--- a/src/gpu/GrPathRendererChain.cpp
+++ b/src/gpu/GrPathRendererChain.cpp
@@ -96,18 +96,29 @@ GrPathRenderer* GrPathRendererChain::getPathRenderer(
         }
     }
 
-    for (int i = 0; i < fChain.count(); ++i) {
-        if (fChain[i]->canDrawPath(args)) {
-            if (GrPathRenderer::kNoSupport_StencilSupport != minStencilSupport) {
-                GrPathRenderer::StencilSupport support = fChain[i]->getStencilSupport(*args.fShape);
-                if (support < minStencilSupport) {
-                    continue;
-                } else if (stencilSupport) {
-                    *stencilSupport = support;
-                }
+    GrPathRenderer* bestPathRenderer = nullptr;
+    for (const sk_sp<GrPathRenderer>& pr : fChain) {
+        GrPathRenderer::StencilSupport support = GrPathRenderer::kNoSupport_StencilSupport;
+        if (GrPathRenderer::kNoSupport_StencilSupport != minStencilSupport) {
+            support = pr->getStencilSupport(*args.fShape);
+            if (support < minStencilSupport) {
+                continue;
             }
-            return fChain[i].get();
+        }
+        GrPathRenderer::CanDrawPath canDrawPath = pr->canDrawPath(args);
+        if (GrPathRenderer::CanDrawPath::kNo == canDrawPath) {
+            continue;
+        }
+        if (GrPathRenderer::CanDrawPath::kAsBackup == canDrawPath && bestPathRenderer) {
+            continue;
+        }
+        if (stencilSupport) {
+            *stencilSupport = support;
+        }
+        bestPathRenderer = pr.get();
+        if (GrPathRenderer::CanDrawPath::kYes == canDrawPath) {
+            break;
         }
     }
-    return nullptr;
+    return bestPathRenderer;
 }
diff --git a/src/gpu/GrSoftwarePathRenderer.cpp b/src/gpu/GrSoftwarePathRenderer.cpp
index 5780cee4e8..37433ff0c4 100644
--- a/src/gpu/GrSoftwarePathRenderer.cpp
+++ b/src/gpu/GrSoftwarePathRenderer.cpp
@@ -22,11 +22,16 @@
 #include "ops/GrRectOpFactory.h"
 
 ////////////////////////////////////////////////////////////////////////////////
-bool GrSoftwarePathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
+GrPathRenderer::CanDrawPath
+GrSoftwarePathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
     // Pass on any style that applies. The caller will apply the style if a suitable renderer is
     // not found and try again with the new GrShape.
-    return !args.fShape->style().applies() && SkToBool(fResourceProvider) &&
-           (args.fAAType == GrAAType::kCoverage || args.fAAType == GrAAType::kNone);
+    if (!args.fShape->style().applies() && SkToBool(fResourceProvider) &&
+        (args.fAAType == GrAAType::kCoverage || args.fAAType == GrAAType::kNone)) {
+        // This is the fallback renderer for when a path is too complicated for the GPU ones.
+        return CanDrawPath::kAsBackup;
+    }
+    return CanDrawPath::kNo;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/src/gpu/GrSoftwarePathRenderer.h b/src/gpu/GrSoftwarePathRenderer.h
index 2421fa4d70..d36b2f6486 100644
--- a/src/gpu/GrSoftwarePathRenderer.h
+++ b/src/gpu/GrSoftwarePathRenderer.h
@@ -53,7 +53,7 @@ private:
         return GrPathRenderer::kNoSupport_StencilSupport;
     }
 
-    bool onCanDrawPath(const CanDrawPathArgs&) const override;
+    CanDrawPath onCanDrawPath(const CanDrawPathArgs&) const override;
 
     bool onDrawPath(const DrawPathArgs&) override;
 
diff --git a/src/gpu/ccpr/GrCoverageCountingPathRenderer.cpp b/src/gpu/ccpr/GrCoverageCountingPathRenderer.cpp
index 2bec4ffeb1..4aff0a918c 100644
--- a/src/gpu/ccpr/GrCoverageCountingPathRenderer.cpp
+++ b/src/gpu/ccpr/GrCoverageCountingPathRenderer.cpp
@@ -39,17 +39,22 @@ GrCoverageCountingPathRenderer::CreateIfSupported(const GrCaps& caps) {
                                                  new GrCoverageCountingPathRenderer : nullptr);
 }
 
-bool GrCoverageCountingPathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
+GrPathRenderer::CanDrawPath
+GrCoverageCountingPathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
     if (!args.fShape->style().isSimpleFill() ||
         args.fShape->inverseFilled() ||
         args.fViewMatrix->hasPerspective() ||
         GrAAType::kCoverage != args.fAAType) {
-        return false;
+        return CanDrawPath::kNo;
     }
 
     SkPath path;
     args.fShape->asPath(&path);
-    return !SkPathPriv::ConicWeightCnt(path);
+    if (SkPathPriv::ConicWeightCnt(path)) {
+        return CanDrawPath::kNo;
+    }
+
+    return CanDrawPath::kYes;
 }
 
 bool GrCoverageCountingPathRenderer::onDrawPath(const DrawPathArgs& args) {
diff --git a/src/gpu/ccpr/GrCoverageCountingPathRenderer.h b/src/gpu/ccpr/GrCoverageCountingPathRenderer.h
index e1e28a40bc..d7617281a2 100644
--- a/src/gpu/ccpr/GrCoverageCountingPathRenderer.h
+++ b/src/gpu/ccpr/GrCoverageCountingPathRenderer.h
@@ -38,7 +38,7 @@ public:
     StencilSupport onGetStencilSupport(const GrShape&) const override {
         return GrPathRenderer::kNoSupport_StencilSupport;
     }
-    bool onCanDrawPath(const CanDrawPathArgs& args) const override;
+    CanDrawPath onCanDrawPath(const CanDrawPathArgs& args) const override;
     bool onDrawPath(const DrawPathArgs&) final;
 
     // GrOnFlushCallbackObject overrides.
diff --git a/src/gpu/ops/GrAAConvexPathRenderer.cpp b/src/gpu/ops/GrAAConvexPathRenderer.cpp
index 425dbae148..0fe74433ff 100644
--- a/src/gpu/ops/GrAAConvexPathRenderer.cpp
+++ b/src/gpu/ops/GrAAConvexPathRenderer.cpp
@@ -665,10 +665,14 @@ sk_sp<GrGeometryProcessor> QuadEdgeEffect::TestCreate(GrProcessorTestData* d) {
 
 ///////////////////////////////////////////////////////////////////////////////
 
-bool GrAAConvexPathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
-    return (args.fCaps->shaderCaps()->shaderDerivativeSupport() &&
-            (GrAAType::kCoverage == args.fAAType) && args.fShape->style().isSimpleFill() &&
-            !args.fShape->inverseFilled() && args.fShape->knownToBeConvex());
+GrPathRenderer::CanDrawPath
+GrAAConvexPathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
+    if (args.fCaps->shaderCaps()->shaderDerivativeSupport() &&
+        (GrAAType::kCoverage == args.fAAType) && args.fShape->style().isSimpleFill() &&
+        !args.fShape->inverseFilled() && args.fShape->knownToBeConvex()) {
+        return CanDrawPath::kYes;
+    }
+    return CanDrawPath::kNo;
 }
 
 // extract the result vertices and indices from the GrAAConvexTessellator
diff --git a/src/gpu/ops/GrAAConvexPathRenderer.h b/src/gpu/ops/GrAAConvexPathRenderer.h
index 420ca60139..a31d6b9593 100644
--- a/src/gpu/ops/GrAAConvexPathRenderer.h
+++ b/src/gpu/ops/GrAAConvexPathRenderer.h
@@ -15,7 +15,7 @@ public:
     GrAAConvexPathRenderer();
 
 private:
-    bool onCanDrawPath(const CanDrawPathArgs&) const override;
+    CanDrawPath onCanDrawPath(const CanDrawPathArgs&) const override;
 
     bool onDrawPath(const DrawPathArgs&) override;
 };
diff --git a/src/gpu/ops/GrAAHairLinePathRenderer.cpp b/src/gpu/ops/GrAAHairLinePathRenderer.cpp
index e00ca3fd5d..ba72eacd7e 100644
--- a/src/gpu/ops/GrAAHairLinePathRenderer.cpp
+++ b/src/gpu/ops/GrAAHairLinePathRenderer.cpp
@@ -677,26 +677,27 @@ static void add_line(const SkPoint p[2],
 
 ///////////////////////////////////////////////////////////////////////////////
 
-bool GrAAHairLinePathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
+GrPathRenderer::CanDrawPath
+GrAAHairLinePathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
     if (GrAAType::kCoverage != args.fAAType) {
-        return false;
+        return CanDrawPath::kNo;
     }
 
     if (!IsStrokeHairlineOrEquivalent(args.fShape->style(), *args.fViewMatrix, nullptr)) {
-        return false;
+        return CanDrawPath::kNo;
     }
 
     // We don't currently handle dashing in this class though perhaps we should.
     if (args.fShape->style().pathEffect()) {
-        return false;
+        return CanDrawPath::kNo;
     }
 
     if (SkPath::kLine_SegmentMask == args.fShape->segmentMask() ||
         args.fCaps->shaderCaps()->shaderDerivativeSupport()) {
-        return true;
+        return CanDrawPath::kYes;
     }
 
-    return false;
+    return CanDrawPath::kNo;
 }
 
 template <class VertexType>
diff --git a/src/gpu/ops/GrAAHairLinePathRenderer.h b/src/gpu/ops/GrAAHairLinePathRenderer.h
index e2406a5c01..b52d5e9959 100644
--- a/src/gpu/ops/GrAAHairLinePathRenderer.h
+++ b/src/gpu/ops/GrAAHairLinePathRenderer.h
@@ -19,7 +19,7 @@ public:
     typedef SkTArray<float, true> FloatArray;
 
 private:
-    bool onCanDrawPath(const CanDrawPathArgs&) const override;
+    CanDrawPath onCanDrawPath(const CanDrawPathArgs&) const override;
 
     bool onDrawPath(const DrawPathArgs&) override;
 
diff --git a/src/gpu/ops/GrAALinearizingConvexPathRenderer.cpp b/src/gpu/ops/GrAALinearizingConvexPathRenderer.cpp
index c1fd4f7e65..d206951ce4 100644
--- a/src/gpu/ops/GrAALinearizingConvexPathRenderer.cpp
+++ b/src/gpu/ops/GrAALinearizingConvexPathRenderer.cpp
@@ -34,39 +34,46 @@ GrAALinearizingConvexPathRenderer::GrAALinearizingConvexPathRenderer() {
 
 ///////////////////////////////////////////////////////////////////////////////
 
-bool GrAALinearizingConvexPathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
+GrPathRenderer::CanDrawPath
+GrAALinearizingConvexPathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
     if (GrAAType::kCoverage != args.fAAType) {
-        return false;
+        return CanDrawPath::kNo;
     }
     if (!args.fShape->knownToBeConvex()) {
-        return false;
+        return CanDrawPath::kNo;
     }
     if (args.fShape->style().pathEffect()) {
-        return false;
+        return CanDrawPath::kNo;
     }
     if (args.fShape->inverseFilled()) {
-        return false;
+        return CanDrawPath::kNo;
     }
     if (args.fShape->bounds().width() <= 0 && args.fShape->bounds().height() <= 0) {
         // Stroked zero length lines should draw, but this PR doesn't handle that case
-        return false;
+        return CanDrawPath::kNo;
     }
     const SkStrokeRec& stroke = args.fShape->style().strokeRec();
 
     if (stroke.getStyle() == SkStrokeRec::kStroke_Style ||
         stroke.getStyle() == SkStrokeRec::kStrokeAndFill_Style) {
         if (!args.fViewMatrix->isSimilarity()) {
-            return false;
+            return CanDrawPath::kNo;
         }
         SkScalar strokeWidth = args.fViewMatrix->getMaxScale() * stroke.getWidth();
         if (strokeWidth < 1.0f && stroke.getStyle() == SkStrokeRec::kStroke_Style) {
-            return false;
+            return CanDrawPath::kNo;
         }
-        return strokeWidth <= kMaxStrokeWidth &&
-               args.fShape->knownToBeClosed() &&
-               stroke.getJoin() != SkPaint::Join::kRound_Join;
+        if (strokeWidth > kMaxStrokeWidth ||
+            !args.fShape->knownToBeClosed() ||
+            stroke.getJoin() == SkPaint::Join::kRound_Join) {
+            return CanDrawPath::kNo;
+        }
+        return CanDrawPath::kYes;
+    }
+    if (stroke.getStyle() != SkStrokeRec::kFill_Style) {
+        return CanDrawPath::kNo;
     }
-    return stroke.getStyle() == SkStrokeRec::kFill_Style;
+    return CanDrawPath::kYes;
 }
 
 // extract the result vertices and indices from the GrAAConvexTessellator
diff --git a/src/gpu/ops/GrAALinearizingConvexPathRenderer.h b/src/gpu/ops/GrAALinearizingConvexPathRenderer.h
index afee5db4d4..4fdcb12a26 100644
--- a/src/gpu/ops/GrAALinearizingConvexPathRenderer.h
+++ b/src/gpu/ops/GrAALinearizingConvexPathRenderer.h
@@ -15,7 +15,7 @@ public:
     GrAALinearizingConvexPathRenderer();
 
 private:
-    bool onCanDrawPath(const CanDrawPathArgs&) const override;
+    CanDrawPath onCanDrawPath(const CanDrawPathArgs&) const override;
 
     bool onDrawPath(const DrawPathArgs&) override;
 };
diff --git a/src/gpu/ops/GrDashLinePathRenderer.cpp b/src/gpu/ops/GrDashLinePathRenderer.cpp
index 38d486c79f..73c2b3e8f2 100644
--- a/src/gpu/ops/GrDashLinePathRenderer.cpp
+++ b/src/gpu/ops/GrDashLinePathRenderer.cpp
@@ -12,18 +12,22 @@
 #include "ops/GrDashOp.h"
 #include "ops/GrMeshDrawOp.h"
 
-bool GrDashLinePathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
+GrPathRenderer::CanDrawPath
+GrDashLinePathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
     SkPoint pts[2];
     bool inverted;
     if (args.fShape->style().isDashed() && args.fShape->asLine(pts, &inverted)) {
         if (args.fAAType == GrAAType::kMixedSamples) {
-            return false;
+            return CanDrawPath::kNo;
         }
         // We should never have an inverse dashed case.
         SkASSERT(!inverted);
-        return GrDashOp::CanDrawDashLine(pts, args.fShape->style(), *args.fViewMatrix);
+        if (!GrDashOp::CanDrawDashLine(pts, args.fShape->style(), *args.fViewMatrix)) {
+            return CanDrawPath::kNo;
+        }
+        return CanDrawPath::kYes;
     }
-    return false;
+    return CanDrawPath::kNo;
 }
 
 bool GrDashLinePathRenderer::onDrawPath(const DrawPathArgs& args) {
diff --git a/src/gpu/ops/GrDashLinePathRenderer.h b/src/gpu/ops/GrDashLinePathRenderer.h
index 11abf99396..23227bc824 100644
--- a/src/gpu/ops/GrDashLinePathRenderer.h
+++ b/src/gpu/ops/GrDashLinePathRenderer.h
@@ -14,7 +14,7 @@ class GrGpu;
 
 class GrDashLinePathRenderer : public GrPathRenderer {
 private:
-    bool onCanDrawPath(const CanDrawPathArgs&) const override;
+    CanDrawPath onCanDrawPath(const CanDrawPathArgs&) const override;
 
     StencilSupport onGetStencilSupport(const GrShape&) const override {
         return kNoSupport_StencilSupport;
diff --git a/src/gpu/ops/GrDefaultPathRenderer.cpp b/src/gpu/ops/GrDefaultPathRenderer.cpp
index e3b48a8db9..9741781013 100644
--- a/src/gpu/ops/GrDefaultPathRenderer.cpp
+++ b/src/gpu/ops/GrDefaultPathRenderer.cpp
@@ -609,15 +609,20 @@ bool GrDefaultPathRenderer::internalDrawPath(GrRenderTargetContext* renderTarget
     return true;
 }
 
-bool GrDefaultPathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
+GrPathRenderer::CanDrawPath
+GrDefaultPathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
     bool isHairline = IsStrokeHairlineOrEquivalent(args.fShape->style(), *args.fViewMatrix, nullptr);
     // If we aren't a single_pass_shape or hairline, we require stencil buffers.
     if (!(single_pass_shape(*args.fShape) || isHairline) && args.fCaps->avoidStencilBuffers()) {
-        return false;
+        return CanDrawPath::kNo;
     }
     // This can draw any path with any simple fill style but doesn't do coverage-based antialiasing.
-    return GrAAType::kCoverage != args.fAAType &&
-           (args.fShape->style().isSimpleFill() || isHairline);
+    if (GrAAType::kCoverage == args.fAAType ||
+        (!args.fShape->style().isSimpleFill() && !isHairline)) {
+        return CanDrawPath::kNo;
+    }
+    // This is the fallback renderer for when a path is too complicated for the others to draw.
+    return CanDrawPath::kAsBackup;
 }
 
 bool GrDefaultPathRenderer::onDrawPath(const DrawPathArgs& args) {
diff --git a/src/gpu/ops/GrDefaultPathRenderer.h b/src/gpu/ops/GrDefaultPathRenderer.h
index 7f7ab2a5e0..f7d98190c2 100644
--- a/src/gpu/ops/GrDefaultPathRenderer.h
+++ b/src/gpu/ops/GrDefaultPathRenderer.h
@@ -23,7 +23,7 @@ public:
 private:
     StencilSupport onGetStencilSupport(const GrShape&) const override;
 
-    bool onCanDrawPath(const CanDrawPathArgs&) const override;
+    CanDrawPath onCanDrawPath(const CanDrawPathArgs&) const override;
 
     bool onDrawPath(const DrawPathArgs&) override;
 
diff --git a/src/gpu/ops/GrMSAAPathRenderer.cpp b/src/gpu/ops/GrMSAAPathRenderer.cpp
index ef19367f61..b80a811430 100644
--- a/src/gpu/ops/GrMSAAPathRenderer.cpp
+++ b/src/gpu/ops/GrMSAAPathRenderer.cpp
@@ -682,15 +682,18 @@ bool GrMSAAPathRenderer::internalDrawPath(GrRenderTargetContext* renderTargetCon
     return true;
 }
 
-bool GrMSAAPathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
+GrPathRenderer::CanDrawPath GrMSAAPathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
     // If we aren't a single_pass_shape, we require stencil buffers.
     if (!single_pass_shape(*args.fShape) && args.fCaps->avoidStencilBuffers()) {
-        return false;
+        return CanDrawPath::kNo;
     }
     // This path renderer only fills and relies on MSAA for antialiasing. Stroked shapes are
     // handled by passing on the original shape and letting the caller compute the stroked shape
     // which will have a fill style.
-    return args.fShape->style().isSimpleFill() && (GrAAType::kCoverage != args.fAAType);
+    if (!args.fShape->style().isSimpleFill() || GrAAType::kCoverage == args.fAAType) {
+        return CanDrawPath::kNo;
+    }
+    return CanDrawPath::kYes;
 }
 
 bool GrMSAAPathRenderer::onDrawPath(const DrawPathArgs& args) {
diff --git a/src/gpu/ops/GrMSAAPathRenderer.h b/src/gpu/ops/GrMSAAPathRenderer.h
index 13d3e15a7e..1353867f16 100644
--- a/src/gpu/ops/GrMSAAPathRenderer.h
+++ b/src/gpu/ops/GrMSAAPathRenderer.h
@@ -15,7 +15,7 @@ class SK_API GrMSAAPathRenderer : public GrPathRenderer {
 private:
     StencilSupport onGetStencilSupport(const GrShape&) const override;
 
-    bool onCanDrawPath(const CanDrawPathArgs&) const override;
+    CanDrawPath onCanDrawPath(const CanDrawPathArgs&) const override;
 
     bool onDrawPath(const DrawPathArgs&) override;
 
diff --git a/src/gpu/ops/GrSmallPathRenderer.cpp b/src/gpu/ops/GrSmallPathRenderer.cpp
index cfdf8734c9..1b0648615d 100644
--- a/src/gpu/ops/GrSmallPathRenderer.cpp
+++ b/src/gpu/ops/GrSmallPathRenderer.cpp
@@ -81,30 +81,30 @@ GrSmallPathRenderer::~GrSmallPathRenderer() {
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-bool GrSmallPathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
+GrPathRenderer::CanDrawPath GrSmallPathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
     if (!args.fCaps->shaderCaps()->shaderDerivativeSupport()) {
-        return false;
+        return CanDrawPath::kNo;
     }
     // If the shape has no key then we won't get any reuse.
     if (!args.fShape->hasUnstyledKey()) {
-        return false;
+        return CanDrawPath::kNo;
     }
     // This only supports filled paths, however, the caller may apply the style to make a filled
     // path and try again.
     if (!args.fShape->style().isSimpleFill()) {
-        return false;
+        return CanDrawPath::kNo;
     }
     // This does non-inverse coverage-based antialiased fills.
     if (GrAAType::kCoverage != args.fAAType) {
-        return false;
+        return CanDrawPath::kNo;
     }
     // TODO: Support inverse fill
     if (args.fShape->inverseFilled()) {
-        return false;
+        return CanDrawPath::kNo;
     }
     // currently don't support perspective
     if (args.fViewMatrix->hasPerspective()) {
-        return false;
+        return CanDrawPath::kNo;
     }
 
     // Only support paths with bounds within kMaxDim by kMaxDim,
@@ -112,15 +112,18 @@ bool GrSmallPathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
     // The goal is to accelerate rendering of lots of small paths that may be scaling.
     SkScalar scaleFactors[2];
     if (!args.fViewMatrix->getMinMaxScales(scaleFactors)) {
-        return false;
+        return CanDrawPath::kNo;
     }
     SkRect bounds = args.fShape->styledBounds();
     SkScalar minDim = SkMinScalar(bounds.width(), bounds.height());
     SkScalar maxDim = SkMaxScalar(bounds.width(), bounds.height());
     SkScalar minSize = minDim * SkScalarAbs(scaleFactors[0]);
     SkScalar maxSize = maxDim * SkScalarAbs(scaleFactors[1]);
+    if (maxDim > kMaxDim || kMinSize > minSize || maxSize > kMaxSize) {
+        return CanDrawPath::kNo;
+    }
 
-    return maxDim <= kMaxDim && kMinSize <= minSize && maxSize <= kMaxSize;
+    return CanDrawPath::kYes;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/src/gpu/ops/GrSmallPathRenderer.h b/src/gpu/ops/GrSmallPathRenderer.h
index d10c4baa86..b958baa843 100644
--- a/src/gpu/ops/GrSmallPathRenderer.h
+++ b/src/gpu/ops/GrSmallPathRenderer.h
@@ -31,7 +31,7 @@ private:
         return GrPathRenderer::kNoSupport_StencilSupport;
     }
 
-    bool onCanDrawPath(const CanDrawPathArgs&) const override;
+    CanDrawPath onCanDrawPath(const CanDrawPathArgs&) const override;
 
     bool onDrawPath(const DrawPathArgs&) override;
 
diff --git a/src/gpu/ops/GrStencilAndCoverPathRenderer.cpp b/src/gpu/ops/GrStencilAndCoverPathRenderer.cpp
index 4d86efdc0e..3179ebacc8 100644
--- a/src/gpu/ops/GrStencilAndCoverPathRenderer.cpp
+++ b/src/gpu/ops/GrStencilAndCoverPathRenderer.cpp
@@ -31,18 +31,22 @@ GrStencilAndCoverPathRenderer::GrStencilAndCoverPathRenderer(GrResourceProvider*
     : fResourceProvider(resourceProvider) {
 }
 
-bool GrStencilAndCoverPathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
+GrPathRenderer::CanDrawPath
+GrStencilAndCoverPathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
     // GrPath doesn't support hairline paths. An arbitrary path effect could produce a hairline
     // path.
     if (args.fShape->style().strokeRec().isHairlineStyle() ||
         args.fShape->style().hasNonDashPathEffect()) {
-        return false;
+        return CanDrawPath::kNo;
     }
     if (args.fHasUserStencilSettings) {
-        return false;
+        return CanDrawPath::kNo;
     }
     // doesn't do per-path AA, relies on the target having MSAA.
-    return (GrAAType::kCoverage != args.fAAType);
+    if (GrAAType::kCoverage == args.fAAType) {
+        return CanDrawPath::kNo;
+    }
+    return CanDrawPath::kYes;
 }
 
 static GrPath* get_gr_path(GrResourceProvider* resourceProvider, const GrShape& shape) {
diff --git a/src/gpu/ops/GrStencilAndCoverPathRenderer.h b/src/gpu/ops/GrStencilAndCoverPathRenderer.h
index c896e61545..dda0157a5c 100644
--- a/src/gpu/ops/GrStencilAndCoverPathRenderer.h
+++ b/src/gpu/ops/GrStencilAndCoverPathRenderer.h
@@ -28,7 +28,7 @@ private:
         return GrPathRenderer::kStencilOnly_StencilSupport;
     }
 
-    bool onCanDrawPath(const CanDrawPathArgs&) const override;
+    CanDrawPath onCanDrawPath(const CanDrawPathArgs&) const override;
 
     bool onDrawPath(const DrawPathArgs&) override;
 
diff --git a/src/gpu/ops/GrTessellatingPathRenderer.cpp b/src/gpu/ops/GrTessellatingPathRenderer.cpp
index 641a037bbe..2db4ffcd0d 100644
--- a/src/gpu/ops/GrTessellatingPathRenderer.cpp
+++ b/src/gpu/ops/GrTessellatingPathRenderer.cpp
@@ -132,27 +132,31 @@ private:
 GrTessellatingPathRenderer::GrTessellatingPathRenderer() {
 }
 
-bool GrTessellatingPathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
-    // This path renderer can draw fill styles, and can do screenspace antialiasing via a
-    // one-pixel coverage ramp. It can do convex and concave paths, but we'll leave the convex
-    // ones to simpler algorithms. We pass on paths that have styles, though they may come back
-    // around after applying the styling information to the geometry to create a filled path. In
-    // the non-AA case, We skip paths thta don't have a key since the real advantage of this path
+GrPathRenderer::CanDrawPath
+GrTessellatingPathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
+    // This path renderer can draw fill styles, and can do screenspace antialiasing via a one-pixel
+    // coverage ramp. It can do convex and concave paths, but we'll give simpler algorithms a chance
+    // to draw the convex ones first. We pass on paths that have styles, though they may come back
+    // around after applying the styling information to the geometry to create a filled path. In the
+    // non-AA case, We skip paths that don't have a key since the real advantage of this path
     // renderer comes from caching the tessellated geometry. In the AA case, we do not cache, so we
     // accept paths without keys.
-    if (!args.fShape->style().isSimpleFill() || args.fShape->knownToBeConvex()) {
-        return false;
+    if (!args.fShape->style().isSimpleFill()) {
+        return CanDrawPath::kNo;
     }
     if (GrAAType::kCoverage == args.fAAType) {
         SkPath path;
         args.fShape->asPath(&path);
         if (path.countVerbs() > 10) {
-            return false;
+            return CanDrawPath::kNo;
         }
     } else if (!args.fShape->hasUnstyledKey()) {
-        return false;
+        return CanDrawPath::kNo;
     }
-    return true;
+    if (args.fShape->knownToBeConvex()) {
+        return CanDrawPath::kAsBackup;
+    }
+    return CanDrawPath::kYes;
 }
 
 namespace {
diff --git a/src/gpu/ops/GrTessellatingPathRenderer.h b/src/gpu/ops/GrTessellatingPathRenderer.h
index d5f2c7af9b..7dd50fc6eb 100644
--- a/src/gpu/ops/GrTessellatingPathRenderer.h
+++ b/src/gpu/ops/GrTessellatingPathRenderer.h
@@ -19,7 +19,7 @@ public:
     GrTessellatingPathRenderer();
 
 private:
-    bool onCanDrawPath(const CanDrawPathArgs& ) const override;
+    CanDrawPath onCanDrawPath(const CanDrawPathArgs&) const override;
 
     StencilSupport onGetStencilSupport(const GrShape&) const override {
         return GrPathRenderer::kNoSupport_StencilSupport;