Make cap only affect the keys of GrShapes that are possibly-open

src/gpu/GrShape.h

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrShape_DEFINED
 #define GrShape_DEFINED
 
@@ skipping 102 matching lines @@
             return false;
         }
         if (rrect) {
             *rrect = fRRect;
         }
         return true;
     }
 
     void asPath(SkPath* out) const {
         switch (fType) {
+            case Type::kEmpty:
+                out->reset();
+                break;
             case Type::kRRect:
                 out->reset();
                 out->addRRect(fRRect);
                 break;
             case Type::kPath:
                 *out = *fPath.get();
                 break;
-            case Type::kEmpty:
-                out->reset();
-                break;
         }
     }
 
     /**
+     * Is it known that the shape has no unclosed contours. This means that it will not have
+     * any caps if stroked (modulo the effect of any path effect).
+     */
+    bool knownToBeClosed() const {
+        switch (fType) {
+            case Type::kEmpty:
+                return true;
+            case Type::kRRect:
+                return true;
+            case Type::kPath:
+                return false;
+        }
+        return false;
+    }
+
+    /**
      * Gets the size of the key for the shape represented by this GrShape (ignoring its styling).
      * A negative value is returned if the shape has no key (shouldn't be cached).
      */
     int unstyledKeySize() const;
 
     /**
      * Writes unstyledKeySize() bytes into the provided pointer. Assumes that there is enough
      * space allocated for the key and that unstyledKeySize() does not return a negative value
      * for this shape.
      */
@@ skipping 58 matching lines @@
         return Type::kPath;
     }
 
     Type                        fType;
     SkRRect                     fRRect;
     SkTLazy<SkPath>             fPath;
     GrStyle                     fStyle;
     SkAutoSTArray<8, uint32_t>  fInheritedKey;
 };
 #endif