This reverts commit f41b3411da35929b09009e47cb52474389e42874, reversing
changes made to e33d8d96212f3e337a6660f1eb1118bffc945bf5.
This was a bad check-in due to my mangling uploading a new version of the branch from a different machine.
This reverts https://github.com/flutter/flutter/pull/2639 and will be replaced by https://github.com/flutter/flutter/pull/2640
Rather than managing all the Material Design icons manually, we now
manage them using an icon font. The icon font contains glyphs for each
icon in an efficient vector format.
This patch updates the FLX tooling to include the MaterialIcons font and
updates the Icon widget to use the font instead of asset images.
Fixes#2313Fixes#2218Fixes#2009Fixes#994
