Fix a bug in the Clamp in X direction tiling.

src/core/SkLinearBitmapPipeline_tile.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 SkLinearBitmapPipeline_tile_DEFINED
 #define SkLinearBitmapPipeline_tile_DEFINED
 
@@ skipping 72 matching lines @@
             }
             Span center = span.breakAt(fXMax, dx);
             if (!center.isEmpty()) {
                 next->pointSpan(center);
             }
             if (!span.isEmpty()) {
                 span.clampToSinglePixel({fXMax - 1, y});
                 next->pointSpan(span);
             }
         } else {
-            Span center = span.breakAt(fXMax, dx);
-
-            if (!span.isEmpty()) {
-                span.clampToSinglePixel({fXMax - 1, y});
-                next->pointSpan(span);
+            Span rightClamped = span.breakAt(fXMax, dx);
+            if (!rightClamped.isEmpty()) {
+                rightClamped.clampToSinglePixel({fXMax - 1, y});
+                next->pointSpan(rightClamped);
             }
-            Span leftEdge = center.breakAt(0.0f, dx);
+            Span center = span.breakAt(0.0f, dx);
             if (!center.isEmpty()) {
                 next->pointSpan(center);
             }
-            if (!leftEdge.isEmpty()) {
-                leftEdge.clampToSinglePixel({0.0f, y});
-                next->pointSpan(leftEdge);
+            if (!span.isEmpty()) {
+                span.clampToSinglePixel({0.0f, y});
+                next->pointSpan(span);
             }
         }
         return true;
     }
 
 private:
     const Sk4s     fXsMax;
     const SkScalar fXMax;
 };
 
@@ skipping 299 matching lines @@
 
 private:
     SkScalar fYMax;
     Sk4f     fYsMax;
     Sk4f     fYsCap;
     Sk4f     fYsDoubleInvMax;
 };
 
 }  // namespace
 #endif  // SkLinearBitmapPipeline_tile_DEFINED