Make DCHECK of range shape result more verbose

third_party/WebKit/Source/platform/fonts/shaping/HarfBuzzShaper.cpp

Index: third_party/WebKit/Source/platform/fonts/shaping/HarfBuzzShaper.cpp
diff --git a/third_party/WebKit/Source/platform/fonts/shaping/HarfBuzzShaper.cpp b/third_party/WebKit/Source/platform/fonts/shaping/HarfBuzzShaper.cpp
index ee7ce043a66a001117b7981da386b86cf749c958..7562f9ece9bd4856261f206d59c191991eef2e8f 100644
--- a/third_party/WebKit/Source/platform/fonts/shaping/HarfBuzzShaper.cpp
+++ b/third_party/WebKit/Source/platform/fonts/shaping/HarfBuzzShaper.cpp
@@ -713,8 +713,15 @@ PassRefPtr<ShapeResult> HarfBuzzShaper::Shape(const Font* font,
     if (start < segment_range.end && end > segment_range.start)
       ShapeSegment(&range_data, segment_range, result.Get());
   }
-  DCHECK(!result->NumCharacters() || (start == result->StartIndexForResult() &&
-                                      end == result->EndIndexForResult()));
+
+#if DCHECK_IS_ON()
+  DCHECK_EQ(length, result->NumCharacters());
+  if (length) {
+    DCHECK_EQ(start, result->StartIndexForResult());
+    DCHECK_EQ(end, result->EndIndexForResult());
+  }
+#endif
+
   return result.Release();
 }