Get rid of unused function ShapeResult::MutableUnique()

This patch gets rid of |unused function ShapeResult::MutableUnique()|
for improving code health.

Change-Id: I6ab5c02b8ee6d92128fd44486212c9df56fba8d9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2412117
Auto-Submit: Yoshifumi Inoue <yosin@chromium.org>
Reviewed-by: Koji Ishii <kojii@chromium.org>
Reviewed-by: Kent Tamura <tkent@chromium.org>
Commit-Queue: Koji Ishii <kojii@chromium.org>
Commit-Queue: Yoshifumi Inoue <yosin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#807373}

third_party/blink/renderer/platform/fonts/shaping/harfbuzz_shaper_test.cc

@@ -203,22 +203,6 @@ INSTANTIATE_TEST_SUITE_P(HarfBuzzShaperTest,
                          testing::Values(TextDirection::kLtr,
                                          TextDirection::kRtl));
 
-TEST_F(HarfBuzzShaperTest, MutableUnique) {
-  scoped_refptr<ShapeResult> result =
-      ShapeResult::Create(&font, 0, 0, TextDirection::kLtr);
-  EXPECT_TRUE(result->HasOneRef());
-
-  // At this point, |result| has only one ref count.
-  scoped_refptr<ShapeResult> result2 = result->MutableUnique();
-  EXPECT_EQ(result.get(), result2.get());
-  EXPECT_FALSE(result2->HasOneRef());
-
-  // Since |result| has 2 ref counts, it should return a clone.
-  scoped_refptr<ShapeResult> result3 = result->MutableUnique();
-  EXPECT_NE(result.get(), result3.get());
-  EXPECT_TRUE(result3->HasOneRef());
-}
-
 TEST_F(HarfBuzzShaperTest, ResolveCandidateRunsLatin) {
   String latin_common = To16Bit("ABC DEF.", 8);
   HarfBuzzShaper shaper(latin_common);

third_party/blink/renderer/platform/fonts/shaping/shape_result.cc

@@ -414,12 +414,6 @@ size_t ShapeResult::ByteSize() const {
   return self_byte_size;
 }
 
-scoped_refptr<ShapeResult> ShapeResult::MutableUnique() const {
-  if (HasOneRef())
-    return const_cast<ShapeResult*>(this);
-  return ShapeResult::Create(*this);
-}
-
 unsigned ShapeResult::NextSafeToBreakOffset(unsigned index) const {
   for (auto* it = runs_.begin(); it != runs_.end(); ++it) {
     const auto& run = *it;

third_party/blink/renderer/platform/fonts/shaping/shape_result.h

@@ -155,10 +155,6 @@ class PLATFORM_EXPORT ShapeResult : public RefCounted<ShapeResult> {
       const OpenTypeMathStretchData::AssemblyParameters&);
   ~ShapeResult();
 
-  // Returns a mutable unique instance. If |this| has more than 1 ref count,
-  // a clone is created.
-  scoped_refptr<ShapeResult> MutableUnique() const;
-
   // The logical width of this result.
   float Width() const { return width_; }
   LayoutUnit SnappedWidth() const { return LayoutUnit::FromFloatCeil(width_); }