add support for capped hairlines

src/core/SkDraw.cpp

Index: src/core/SkDraw.cpp
diff --git a/src/core/SkDraw.cpp b/src/core/SkDraw.cpp
index e1a49d39b4a582265dda15c430ffbf95578bc297..afa2c9dda95265f8f8fd5f0810681d2bfa3846b8 100644
--- a/src/core/SkDraw.cpp
+++ b/src/core/SkDraw.cpp
@@ -1132,9 +1132,23 @@ void SkDraw::drawPath(const SkPath& origSrcPath, const SkPaint& origPaint,
         }
     } else {    // hairline
         if (paint->isAntiAlias()) {
+            if (SkPaint::kButt_Cap == paint->getStrokeCap()) {
+                proc = SkScan::AntiHairPath;
+            } else {
+                proc = SkScan::AntiHairCapPath;
+            }
+#ifdef SK_SUPPORT_LEGACY_HAIR_IGNORES_CAPS
             proc = SkScan::AntiHairPath;
+#endif
         } else {
-            proc = SkScan::HairPath;
+            if (SkPaint::kButt_Cap == paint->getStrokeCap()) {
+                proc = SkScan::HairPath;
+            } else {
+                proc = SkScan::HairCapPath;
+            }
+#ifdef SK_SUPPORT_LEGACY_HAIR_IGNORES_CAPS
+            proc = SkScan::AntiHairPath;
+#endif
         }
     }
     proc(*devPathPtr, *fRC, blitter);