Add float version of gfx::Range

ui/gfx/render_text_harfbuzz.cc

Index: ui/gfx/render_text_harfbuzz.cc
diff --git a/ui/gfx/render_text_harfbuzz.cc b/ui/gfx/render_text_harfbuzz.cc
index 82580b3961f5d475e71b407b70839cc35b8cc6be..e4a0dd6b9a66d366e070446b0bc4d236252fdb94 100644
--- a/ui/gfx/render_text_harfbuzz.cc
+++ b/ui/gfx/render_text_harfbuzz.cc
@@ -25,7 +25,6 @@
 #include "ui/gfx/font_fallback_win.h"
 #endif
 
-using gfx::internal::RangeF;
 using gfx::internal::RoundRangeF;
 
 namespace gfx {
@@ -469,8 +468,8 @@ void GetClusterAtImpl(size_t pos,
 namespace internal {
 
 Range RoundRangeF(const RangeF& range_f) {
-  return Range(std::floor(range_f.first + 0.5f),
-               std::floor(range_f.second + 0.5f));
+  return Range(std::floor(range_f.start() + 0.5f),
+               std::floor(range_f.end() + 0.5f));
 }
 
 TextRunHarfBuzz::TextRunHarfBuzz()
@@ -666,9 +665,9 @@ Range RenderTextHarfBuzz::GetGlyphBounds(size_t index) {
   // position since clients expect them to be contiguous.
   if (cursor_enabled() && run_index == runs_.size() - 1 &&
       index == (run->is_rtl ? run->range.start() : run->range.end() - 1))
-    bounds.second = std::ceil(bounds.second);
+    bounds.set_end(std::ceil(bounds.end()));
   return RoundRangeF(run->is_rtl ?
-      RangeF(bounds.second, bounds.first) : bounds);
+      RangeF(bounds.end(), bounds.start()) : bounds);
 }
 
 int RenderTextHarfBuzz::GetLayoutTextBaseline() {