Synchronizes dartdoc with dart:ui
Synchronizes dartdoc with dart:ui

Mostly just adds some examples to match the examples with use for
similar concepts in dart:ui.

tvolkert/flutter,cbracken/flutter,turnidge/flutter,turnidge/flutter,turnidge/flutter,turnidge/flutter,tvolkert/flutter,cbracken/flutter,flutter/flutter,aghassemi/flutter,aghassemi/flutter,flutter/flutter,turnidge/flutter,Hixie/flutter,flutter/flutter,Hixie/flutter,flutter/flutter,Hixie/flutter,Hixie/flutter,Hixie/flutter,Hixie/flutter,tvolkert/flutter,cbracken/flutter,Hixie/flutter,cbracken/flutter,tvolkert/flutter,flutter/flutter,tvolkert/flutter,Hixie/flutter,cbracken/flutter,flutter/flutter,tvolkert/flutter,cbracken/flutter,tvolkert/flutter,tvolkert/flutter,Hixie/flutter,flutter/flutter,flutter/flutter,tvolkert/flutter,flutter/flutter,aghassemi/flutter,cbracken/flutter,aghassemi/flutter,cbracken/flutter,flutter/flutter,Hixie/flutter,tvolkert/flutter,cbracken/flutter,cbracken/flutter