remove legacy switch

Chrome tests have been rebased
and legacy define has been removed,
so remove from Skia as well.

R=fmalita@chromium.org

Bug:843966
Change-Id: I3794b8457c581f71d4bd30eb81d6fa4c8a589cad
Reviewed-on: https://skia-review.googlesource.com/c/176224
Auto-Submit: Cary Clark <caryclark@skia.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>
Reviewed-by: Florin Malita <fmalita@chromium.org>

Author: Cary Clark

src/core/SkStroke.cpp

@@ -591,11 +591,7 @@ static bool quad_in_line(const SkPoint quad[3]) {
     SkASSERT(outer2 >= 1 && outer2 <= 2);
     SkASSERT(outer1 < outer2);
     int mid = outer1 ^ outer2 ^ 3;
-#ifdef SK_USE_LEGACY_CONIC_CURVATURE_SLOP
-    const float kCurvatureSlop = 0.00001f;
-#else
     const float kCurvatureSlop = 0.000005f;  // this multiplier is pulled out of the air
-#endif
     SkScalar lineSlop =  ptMax * ptMax * kCurvatureSlop;
     return pt_to_line(quad[mid], quad[outer1], quad[outer2]) <= lineSlop;
 }
@@ -656,16 +652,9 @@ SkPathStroker::ReductionType SkPathStroker::CheckConicLinear(const SkConic& coni
     if (!conic_in_line(conic)) {
         return kQuad_ReductionType;
     }
-#ifdef SK_USE_LEGACY_CONIC_CURVATURE_SLOP
-    SkScalar xT = 0, yT = 0;
-    (void) conic.findXExtrema(&xT);
-    (void) conic.findYExtrema(&yT);
-    SkScalar t = SkTMax(xT, yT);
-#else
     // SkFindConicMaxCurvature would be a better solution, once we know how to
     // implement it. Quad curvature is a reasonable substitute
     SkScalar t = SkFindQuadMaxCurvature(conic.fPts);
-#endif
     if (0 == t) {
         return kLine_ReductionType;
     }