Pass and return GrColor4h by const& when possible

Bug: skia:
Change-Id: I8486d0631e4723f1a457a607bc21abd2581133d8
Reviewed-on: https://skia-review.googlesource.com/c/166562
Commit-Queue: Brian Osman <brianosman@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
Auto-Submit: Brian Osman <brianosman@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
diff --git a/src/gpu/ops/GrDefaultPathRenderer.cpp b/src/gpu/ops/GrDefaultPathRenderer.cpp
index f542961..afb63c9 100644
--- a/src/gpu/ops/GrDefaultPathRenderer.cpp
+++ b/src/gpu/ops/GrDefaultPathRenderer.cpp
@@ -372,7 +372,7 @@
         return string;
     }
 
-    DefaultPathOp(const Helper::MakeArgs& helperArgs, GrColor4h color, const SkPath& path,
+    DefaultPathOp(const Helper::MakeArgs& helperArgs, const GrColor4h& color, const SkPath& path,
                   SkScalar tolerance, uint8_t coverage, const SkMatrix& viewMatrix, bool isHairline,
                   GrAAType aaType, const SkRect& devBounds,
                   const GrUserStencilSettings* stencilSettings)
@@ -465,7 +465,7 @@
         return CombineResult::kMerged;
     }
 
-    GrColor4h color() const { return fColor; }
+    const GrColor4h& color() const { return fColor; }
     uint8_t coverage() const { return fCoverage; }
     const SkMatrix& viewMatrix() const { return fViewMatrix; }
     bool isHairline() const { return fIsHairline; }