Text snaps to pixel grid, images don't
Text snaps to pixel grid, images don't

Previously, we tried to use the render tree's paint offset to move the text to
the proper position, but that appears to snap to integer logical pixels,
introducing jitter. Now we use the SkCanvas's matrix to position the text,
removing the jitter.

Fixes https://github.com/flutter/flutter/issues/234

jason-simmons/flutter_engine,tvolkert/engine,jamesr/flutter_engine,krisgiesing/sky_engine,mikejurka/engine,jason-simmons/sky_engine,devoncarew/engine,Hixie/sky_engine,mpcomplete/engine,devoncarew/sky_engine,rmacnak-google/engine,Hixie/sky_engine,abarth/sky_engine,tvolkert/engine,aam/engine,jamesr/flutter_engine,devoncarew/engine,tvolkert/engine,jason-simmons/sky_engine,mikejurka/engine,jason-simmons/sky_engine,Hixie/sky_engine,chinmaygarde/sky_engine,abarth/sky_engine,cdotstout/sky_engine,jamesr/flutter_engine,Hixie/sky_engine,flutter/engine,Hixie/sky_engine,aam/engine,mpcomplete/engine,abarth/sky_engine,flutter/engine,mpcomplete/flutter_engine,devoncarew/engine,chinmaygarde/sky_engine,mikejurka/engine,mpcomplete/engine,jason-simmons/flutter_engine,chinmaygarde/sky_engine,lyceel/engine,aam/engine,devoncarew/engine,mpcomplete/engine,chinmaygarde/sky_engine,jamesr/flutter_engine,tvolkert/engine,devoncarew/sky_engine,jason-simmons/sky_engine,aam/engine,jamesr/sky_engine,krisgiesing/sky_engine,jason-simmons/sky_engine,devoncarew/sky_engine,jamesr/sky_engine,mikejurka/engine,flutter/engine,Hixie/sky_engine,flutter/engine,Hixie/sky_engine,jamesr/flutter_engine,mpcomplete/flutter_engine,jason-simmons/flutter_engine,chinmaygarde/flutter_engine,flutter/engine,mpcomplete/flutter_engine,lyceel/engine,tvolkert/engine,jason-simmons/flutter_engine,jamesr/sky_engine,chinmaygarde/flutter_engine,chinmaygarde/flutter_engine,jamesr/sky_engine,jamesr/flutter_engine,mpcomplete/flutter_engine,mpcomplete/engine,mikejurka/engine,jamesr/sky_engine,mpcomplete/engine,mpcomplete/flutter_engine,krisgiesing/sky_engine,devoncarew/sky_engine,chinmaygarde/flutter_engine,cdotstout/sky_engine,flutter/engine,jason-simmons/flutter_engine,jason-simmons/flutter_engine,tvolkert/engine,jamesr/flutter_engine,jamesr/sky_engine,jason-simmons/sky_engine,cdotstout/sky_engine,Hixie/sky_engine,mpcomplete/engine,flutter/engine,rmacnak-google/engine,aam/engine,mikejurka/engine,jason-simmons/flutter_engine,krisgiesing/sky_engine,cdotstout/sky_engine,abarth/sky_engine,mikejurka/engine,rmacnak-google/engine,rmacnak-google/engine,tvolkert/engine,mpcomplete/flutter_engine,aam/engine,cdotstout/sky_engine,devoncarew/sky_engine,krisgiesing/sky_engine,rmacnak-google/engine,lyceel/engine,jamesr/flutter_engine,devoncarew/engine,rmacnak-google/engine,abarth/sky_engine,mikejurka/engine,devoncarew/engine,chinmaygarde/flutter_engine,devoncarew/sky_engine,chinmaygarde/sky_engine,jason-simmons/flutter_engine,lyceel/engine,abarth/sky_engine,flutter/engine,jason-simmons/sky_engine,mikejurka/engine,lyceel/engine,lyceel/engine,krisgiesing/sky_engine,jamesr/sky_engine,lyceel/engine,chinmaygarde/sky_engine,devoncarew/engine,chinmaygarde/flutter_engine,mpcomplete/engine,chinmaygarde/flutter_engine,chinmaygarde/sky_engine,cdotstout/sky_engine,krisgiesing/sky_engine,rmacnak-google/engine,abarth/sky_engine,cdotstout/sky_engine,jamesr/flutter_engine,devoncarew/sky_engine,aam/engine,aam/engine