Remove trailing whitespace.

Also adds a presubmit to prevent adding trailing whitespace to source
code in the future.

Change-Id: I41a4df81487f6f00aa19b188f0cac6a3377efde6
Reviewed-on: https://skia-review.googlesource.com/57380
Reviewed-by: Ravi Mistry <rmistry@google.com>
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
diff --git a/src/gpu/GrTessellator.h b/src/gpu/GrTessellator.h
index a09b7c2..4f82ea8 100644
--- a/src/gpu/GrTessellator.h
+++ b/src/gpu/GrTessellator.h
@@ -46,7 +46,7 @@
 int PathToVertices(const SkPath& path, SkScalar tolerance, const SkRect& clipBounds,
                    WindingVertex** verts);
 
-int PathToTriangles(const SkPath& path, SkScalar tolerance, const SkRect& clipBounds, 
+int PathToTriangles(const SkPath& path, SkScalar tolerance, const SkRect& clipBounds,
                     VertexAllocator*, bool antialias, const GrColor& color,
                     bool canTweakAlphaForCoverage, bool *isLinear);
 }