MacViews: Implement Force Touch/Mac dictionary lookup for Textfields.

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 d0b3dd7200278cbaadb91c086ddda01ec5a6638b..fbfe3efe377f7bb8d94a8723a41b998bc779f886 100644
--- a/ui/gfx/render_text_harfbuzz.cc
+++ b/ui/gfx/render_text_harfbuzz.cc
@@ -1590,4 +1590,14 @@ const internal::TextRunList* RenderTextHarfBuzz::GetRunList() const {
   return const_cast<RenderTextHarfBuzz*>(this)->GetRunList();
 }
 
+#if !defined(OS_MACOSX)
+bool RenderTextHarfBuzz::GetStyledStringForRange(const Range& range,
+                                                 base::string16* str) const {
+  if (obscured())
+    return false;
+  *str = GetTextFromRange(range);
+  return true;
+}
+#endif
+
 }  // namespace gfx